Scholarly Interest Report


 

Qimiao Si  Professor  Harry C. and Olga K. Wiess Professor of Physics and Astronomy   email:qmsi@rice.edu    B.S., University of Science and Technology of China, 1986
 Ph.D., University of Chicago, 1991
 Alfred P. Sloan Research Fellow
 Humboldt Research Award
 Fellow, Institute of Physics (U.K.)
 Fellow, AAAS (American Association for the Advancement of Science)
 Fellow, American Physical Society
 Phone: 7133485204; Fax: 7133484150
  Primary Department  Department of Physics and Astronomy     Department Affiliations   Rice Quantum InstituteSmalley Institute for Nanoscale Science and TechnologyWiess School of Natural Sciences  
Websites   Rice Center for Quantum Materials
  Condensed Matter Physics @ Rice University
  Condensed Matter Seminars
  Keck Program in Quantum Materials
  Recent publications  search arxiv.org
 
Research Areas   Theoretical Condensed matter physics, specializing in strongly correlated electron systems.  
Biographical Sketch   Qimiao Si is the Harry C. and Olga K. Wiess Professor of Physics and Astronomy at Rice University. He came to the United States through the highly selective CUSPEA program in 1986, upon earning his B.S. in Physics from University of Science and Technology of China. He received his Ph.D. in Physics in 1991 from the University of Chicago and subsequently did postdoctoral work at Rutgers University and University of Illinois at UrbanaChampaign. He has been on the faculty of Rice University since 1994 (making the actual move to Rice in 1995, after a year's leave of absence).
Prof. Si works in the field of theoretical condensed matter physics. His major contributions have been in the area of strongly correlated electron systems, including quantum criticality and emergent quantum phases, magnetic heavy fermion metals, high temperature superconductors, and mesoscopic and disordered electronic systems.
He is particularly well known for his contributions to the theory of quantum criticality, which concerns the physics of matter undergoing a transition from one quantum state to another. He introduced and developed the theory of local quantum criticality, which involves the notion of critical destruction of Kondo entanglement. The theory goes beyond the Landau framework, and has received extensive support from experiments in magnetic heavy fermion systems. He has made seminal contributions to the young field of ironbased superconductors, contributing broadly to the understanding of electron correlations, quantum criticality, magnetism and superconductivity. He has introduced the BoseFermi Kondo model and the method of the extended dynamical mean field theory, and contributed to the early development of the dynamical mean field theory. Other topics he has studied include the spin dynamics of the high temperature cuprate superconductors, metalinsulator transition in disordered and interacting electrons in two dimensions, experimental signatures of spincharge separation, nonFermi liquid states in an extended Hubbard model and in quantum impurity systems, and Mott transition between metallic and correlated insulating phases of interacting electrons.
Prof. Si was named a Sloan Research Fellow in 1996, and received a Cottrell Scholar Award from the Research Corporation for Science Advancement in 1998. He was elected a Fellow of the British Institute of Physics in 2004, the American Physical Society in 2005, and the American Association for the Advancement of Science in 2008. He received a Humboldt Prize from the Alexander von Humboldt Foundation in 2012.
As of December 2015, he has published over 170 scientific articles (including 19 in Science, Nature, Nature Group Journals and PNAS, and 41 in Physical Review Letters) and has given more than 290 invited talks (including over 150 at conferences) on his research. He has served as a General Member of the Aspen Center for Physics (since 2009) and on the Advisory Editorial Board of Journal of Physics  Condensed Matter (20022006), and has cochaired a number of international conferences and workshops, including the 2007 International Conference on Strongly Correlated Electron Systems (SCES'07) and the 2014 KITP Program on Magnetism, Bad Metals and Superconductivity  Iron Pnictides and Beyond.   Research Statement   Qimiao Si works in theoretical condensed matter physics, with an emphasis on quantum magnetism and superconductivity of strongly correlated electron systems.
Strongly correlated electron systems are at the forefront of condensed matter physics. Their theoretical description is a challenge that provides rich opportunities for creative research. The fundamental question is how the electrons are organized, and, in particular, whether there are principles that are universal among the various classes of these strongly correlated materials. The overarching goal of the group's research is to seek such principles of universality. Along the way, it is also fascinating to explore the diversity of the phenomena that result from electron correlations.
One area of Prof. Si's current interest is quantum criticality. He and his collaborators have advanced a by now wellknown theory of local quantum criticality. Developed in the context of magnetic heavy fermion metals, which is a prototype system for quantum phase transitions, this theory features the "beyondLandau" physics of critical Kondo destruction. A related topic of his recent research addresses novel phases that emerge in the vicinity of quantum critical points; for heavy fermion systems, his work here appears in the form of a proposed global phase diagram. He has also been interested in quantum critical physics in a variety of other contexts.
Another focus of Prof. Si's current research concerns ironbased superconductors. One important aspect of the work is to address the badmetal behavior in the normal state, which is attributed to a proximity to delocalizationlocalization transition. This line of consideration has opened up studies on orbitalselective Mott phenomena. A corollary of this approach is that magnetism is primarily driven by J1J2 interactions, a notion that he and his collaborators have pioneered. This approach has led them to theoretically predict a magnetic quantum critical point in isoelectronically tuned iron pnictides, which has been verified by extensive recent experiments. His recent work has also explored the related magnetic frustration physics in the iron chalcogenides, including its effect on the nematicity in FeSe. Finally, the implications of such magnetic interactions for the unconventional superconductivity is being studied; recent work along this direction has shown how high Tc superconductivity may develop in the iron chalcogenides with seemingly unfavorable Fermisurface conditions, and how orbital selectivity gives rise to a new superconducting pairing state.
A variety of other topics in correlated electron systems are of interest to the group. These range from nonFermi liquid behavior, quantum entanglement in manybody systems, cuprate superconductors, disordered and interacting electronic systems, metalinsulator transitions, out of equilibrium behavior of electronic systems, spin transport, and the probe of spincharge separation.
Representative Publications
Qimiao Si, Rong Yu and Elihu Abrahams, "High Temperature Superconductivity in Iron Pnictides and Chalcogenides", Nature Rev. Mater. 1, 16017 (2016). http://www.nature.com/articles/natrevmats201617.
E. M. Nica, K. Ingersent, Qimiao Si, “Quantum criticality and global phase diagram of an Isinganisotropic Kondo lattice”, arXiv:1603.03829.
R. Yu and Qimiao Si, “Antiferroquadrupolar and Isingnematic orders of a frustrated bilinearbiquadratic Heisenberg model and implications for the magnetism of FeSe”, Phys. Rev. Lett. 115, 116401 (2015).
J. H. Pixley, R. Yu, and Qimiao Si, "Quantum phases of the ShastrySutherland Kondo lattice: implications for the global phase diagram of heavy fermion metals", Physical Review Letters 113, 176402 (2014).
X. Lu, J. T. Park, R. Zhang, H. Luo, A. H. Nevidomskyy, Qimiao Si, and P. Dai, “Nematic spin correlations in the tetragonal state of uniaxial strained BaFe(2x)Ni(x)As(2)”, Science 345, 657660 (2014).
R. Yu, P. Goswami, Q. Si, P. Nikolic, and JX Zhu, "Superconductivity at the Border of Electron Localization and Itinerancy", Nature Communications 4, 2783 (2013); doi:10.1038/ncomms3783.
XY Feng, J. Dai, CH Chung, and Q. Si, "Competing topological and Kondo insulator phases on a honeycomb lattice", Physical Review Letters 111, 016402 (2013).
R. Yu and Q. Si, "Orbitalselective Mott phase in multiorbital models for alkaline selenides K(1x)Fe(2y)Se2", Physical Review Letters 110, 146402 (2013).
P. Goswami and Q. Si, "Effects of Berry Phase and Instantons in One Dimensional KondoHeisenberg Model", Physical Review Letters 107, 126404 (2011).
Q. Si and F. Steglich, "Heavy Fermions and Quantum Phase Transitions'', Science 329, 1161 (2010).
P. Goswami, P. Nikolic, and Q. Si, "Superconductivity in Multiorbital tJ1J2 Model and its Implications for Iron Pnictides'', EPL 91, 37006 (2010).
Q. Si, "Quantum Criticality and Global Phase Diagram of Magnetic Heavy Fermions'', Phys. Status Solidi B247, 476 (2010).
J. Dai, Q. Si, J.X. Zhu, and E. Abrahams, "Iron Pnictides as a New Setting for Quantum Criticality", PNAS 106, 4118 (2009).
Q. Si and E. Abrahams, "Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides", Physical Review Letters 101, 076401 (2008).
P. Gegenwart, T. Westerkamp, C. Krellner, Y. Tokiwa, S. Paschen, C. Geibel, F. Steglich, E. Abrahams, and Q. Si, "Multiple energy scales at a quantum critical point", Science 315, 969971 (2007)
S. J. Yamamoto and Q. Si, "Fermi surface and antiferromagnetism in the Kondo lattice: an asymptotically exact solution in d>1 dimensions'', Physical Review Letters 99, 016401 (2007).
S. Kirchner, L. Zhu, Q. Si and D. Natelson, "Quantum Criticality in Ferromagnetic SingleElectron Transistors", PNAS 102, 18824 (2005).
S. Paschen, T. Luhmann, S. Wirth, P. Gegenwart, O. Trovarelli, C. Geibel, F. Steglich, P. Coleman, and Q. Si, "Halleffect evolution across a heavyfermion quantum critical point", Nature 432, 881885 (2004).
L. Zhu, M. Garst, A. Rosch and Q. Si, "Universally Diverging Grueneisen Parameter and the Magnetocaloric Effect close to Quantum Critical Points”, Physical Review Letters 91, 066404 (2003).
Q. Si, S. Rabello, K. Ingersent and J. L. Smith, "Locallycritical Quantum Phase Transitions in Strongly Correlated Metals'', Nature 413, 804 (2001).   Teaching Areas   Physics  
Selected Publications   Refereed articles   E. Schuberth, M. Tippmann, L. Steinke, S. Lausberg, A. Steppke, M. Brando, C. Krellner, C. Geibel, R. Yu, Qimiao Si, and F. Steglich, "Emergence of superconductivity in the canonical heavyelectron metal YbRh2Si2", Science 351, 485488 (2016). http://dx.doi.org/10.1126/science.aaa9733    J. Wu, Qimiao Si, and E. Abrahams, "Magnetic and Ising quantum phase transitions in a model for isoelectronically tuned iron pnictides", Phys. Rev. B93, 104515 (2016). http://link.aps.org/doi/10.1103/PhysRevB.93.104515    Qimiao Si, Rong Yu and Elihu Abrahams, "High Temperature Superconductivity in Iron Pnictides and Chalcogenides", Nature Rev. Mater. 1, 16017 (2016). http://www.nature.com/articles/natrevmats201617    E. M. Nica, R. Yu, and Qimiao Si, "Glide reflection symmetry, Brillouin zone folding and superconducting pairing for the P4/nmm space group", Phys. Rev. B92, 174520 (2015).    E. M. Nica, R. Yu, and Qimiao Si, "Orbital selectivity and emergent superconducting state from quasidegenerate s− and d−wave pairing channels in ironbased superconductors", submitted; arXiv:1505.04170.    F. Eilers, K. Grube, D. A. Zocco, T. Wolf, M. Merz, P. Schweiss, R. Heid, R. Eder, R. Yu, J.X. Zhu, Qimiao Si, T. Shibauchi, and H. v. Lohneysen, "Quantum criticality in AFe2As2 with A=K, Rb and Cs suppresses superconductivity", Phys. Rev. Lett., submitted; arXiv:1510.01857.    H. Man, X. Lu, J. S. Chen, R. Zhang, W. Zhang, H. Luo, J. Kulda, A. Ivanov, T. Keller, E. Morosan, Qimiao Si, and P. Dai, "Electronic nematic correlations in the stress free tetragonal state of BaFe(2x)Ni(x)As2", Phys. Rev. B92, 134521 (2015).    J. H. Pixley, Ang Cai, and Qimiao Si, “Cluster Extended Dynamical Mean Field Approach and Unconventional Superconductivity”, Phys. Rev. B91, 125127 (2015).    J. H. Pixley, Lili Deng, Kevin Ingersent, and Qimiao Si, “Pairing Correlations Near a KondoDestruction Quantum Critical Point”, Phys. Rev. B91, Rapid Commun., 201109(R) (2015).    J. H. Pixley, R. Yu, S. Paschen, and Qimiao Si, "Global Phase Diagram and Momentum Distribution of SingleParticle Excitations in Kondo insulators", Phys. Rev. Lett., submitted; arXiv:1509.02907.    L. Jiao, Y. Chen, Y. Kohama, D. Graf, E. D. Bauer, J. Singleton, J.X. Zhu, Z. F. Weng, G. M. Pang, T. Shang, J. L. Zhang, H. O. Lee, T. Park, M. Jaime, J. D. Thompson, F. Steglich, and Q. Si, and H. Q. Yuan, “Fermisurface reconstruction and multiple quantum phase transitions in the antiferromagnet CeRhIn5”, PNAS 112, 673678 (2015).    M. Yi, Z.K. Liu, Y. Zhang, R. Yu, J.X. Zhu, J. J. Lee, R. G. Moore, F. T. Schmitt, W. Li, S. C. Riggs, J.H. Chu, B. Lv, J. Hu, T. J. Liu, M. Hashimoto, S.K. Mo, Z. Hussain, Z. Q. Mao, C. W. Chu, I. R. Fisher, Q. Si, Z.X. Shen, and D. H. Lu, "Observation of universal strong orbitaldependent correlation effects in iron chalcogenides", Nature Commun. 6, 7777 (2015).    Rong Yu and Qimiao Si, “Antiferroquadrupolar and Isingnematic orders of a frustrated bilinearbiquadratic Heisenberg model and implications for the magnetism of FeSe”, Phys. Rev. Lett. 115, 116401 (2015).    W. Ding, S. Paschen, and Qimiao Si, "Anomalous Hall effect and quantum criticality in geometrically frustrated heavy fermion metals", Phys. Rev. Lett., submitted; arXiv:1507.07328.    Y. Song, X. Lu,, D. L. Abernathy, D. W. Tam, J. L. Niedziela, W. Tian, H. Luo, Qimiao Si, and P. Dai, "Energy dependence of the spin excitation anisotropy in uniaxialstrained BaFe(1.9)Ni(0.1)As2", Phys. Rev. B92, 180504(R) (2015).    Y. Song, Z. Yamani, C.D. Cao, Y. Li, C.L. Zhang, J. Chen, Q. Z. Huang, H. Wu, J. Tao, Y. Zhu, W.Tian, S. X. Chi, R. Yu, Andriy H. Nevidomskyy, Emilia Morosan, Qimiao Si, and Pengcheng Dai, “A Mott insulator induced near iron pnictide superconductors”, submitted (2015); arXiv:1504.05116.    Z. K. Liu, M. Yi, Y. Zhang, J. Hu, R. Yu, J. X. Zhu, R. H. He, Y. L. Chen, M. Hashimoto, R. G. Moore, S. K. Mo, Z. Hussain, Q. Si, Z. Q. Mao, D. H. Lu, Z. X. Shen, "Experimental Observation of IncoherentCoherent Crossover and Orbital Dependent Band Renormalization in Iron Chalcogenide Superconductors", Phys. Rev. B92, 235138 (2015).    Zhang, C., J. T. Park, Xingye Lu, Rong Yu, Yu Li, Wenliang Zhang, Yang Zhao,J. W. Lynn, Qimiao Si, and Pengcheng Dai, “Neutron spin resonance as a probe of superconducting gap anisotropy in partially detwinned electron underdoped NaFe(0.985)Co(0.015)As”, Phys. Rev. B 91, 104520 (2015).    C. Zhang, Y. Su, L.P. Regnault, Y. Su, M. Enderle, J. Julda, G. Tan, Z. C. Sims, T. Egami, Qimiao Si, and P. Dai, "Anisotropic neutron spin resonance in underdoped superconducting NaFe(1x)Co(x)As", Phys. Rev. B90, 140502(R) (2014).    F. Steglich, H. Pfau, S. Lausberg, P. Sun, U. Stockert, M. Brando, S. Friedemann, C. Krellner, C. Geibel, S. Wirth, S. Kirchner, E. Abrahams, and Qimiao Si, "Evidence for a Kondo destroying quantum critical point in YbRh2Si2", J. Phys. Soc. Jpn. 83, 061001 (2014). http://dx.doi.org/10.7566/JPSJ.83.061001    J. H. Pixley, Rong Yu, and Qimiao Si, "Quantum phases of the ShastrySutherland Kondo lattice: implications for the global phase diagram of heavy fermion metals", Phys. Rev. Lett. 113, 176402 (2014) http://dx.doi.org/10.1103/PhysRevLett.113.176402    J. Wu, M. Kormos and Qimiao Si, "Finite temperature spin dynamics in a perturbed quantum critical Ising chain with an E8 symmetry", Phys. Rev. Lett. 113, 247201 (2014). http://dx.doi.org/10.1103/PhysRevLett.113.247201    P. Gao, R. Yu, L. Sun, H. Wang, Z. Wang, Q. Wu, M. Fang, G. Chen, J. Guo, C. Zhang, D. Gu, H. Tian, J. Li, J. Liu, Y. Li, X. Li, Qimiao Si, and Z. Zhao, "Role of the 245 phase in alkaline iron selenide superconductors revealed by highpressure studies", Phys. Rev. B89, 094514 (2014).    Pallab Goswami and Qimiao Si, "Topological defects of Neel order and Kondo singlet formation for KondoHeisenberg model on a honeycomb lattice", Phys. Rev. B89, 045124 (2014).    Qimiao Si, J. H. Pixley, Emilian Nica, Seiji J. Yamamoto, P. Goswami, R. Yu, and S. Kirchner, "Kondo Destruction and Quantum Criticality in Kondo Lattice Systems", J. Phys. Soc. Jpn. 83, 061005 (2014). http://dx.doi.org/10.7566/JPSJ.83.061005    Rong Yu, JianXin Zhu and Qimiao Si, "Orbitalselective superconductivity, gap anisotropy and spin resonance excitations in a multiorbital tJ1J2 model for iron pnictides", Phys. Rev. B 89, 024509 (2014).    W. Ding, R. Yu, Qimiao Si, and E. Abrahams, "Effective Exchange Interactions for Bad Metals and Implications for Ironbased Superconductors", Phys. Rev. Lett., submitted (2014); arXiv:1410.8118.    X. Lu, J. T. Park, R. Zhang, H. Luo, A. H. Nevidomskyy, Qimiao Si, and P. Dai, "Nematic spin correlations in the tetragonal state of uniaxial strained BaFe(2x)Ni(x)As2", Science 345, 657660 (2014). http://dx.doi.org/10.1126/science.1251853    Y. Luo, L. Pourovskii, S. Rowley, Y. Li, C. Feng, A. Georges, J. Dai, G. H. Cao, Z. A. Xu, Qimiao Si, and N. P. Ong, "Heavy Fermion Quantum Criticality and Destruction of the Kondo Effect in a Nickel Oxypnictide'', Nature Materials 13, 777781 (2014). http://dx.doi.org/10.1038/nmat3991    C. Zhang, Rong Yu, Y. Su, Y. Song, M. Wang, G. Tan, T. Egami, J. A. FernandezBaca, E. Faulhaber, Qimiao Si, and P. Dai, "Double spin resonances and gap anisotropy in superconducting Counderdoped NaFeAs", Phys. Rev. Lett. 111, 207002 (2013).    D. D. Khalyavin, D. T. Adroja, P. Manuel, A. DaoudAladine, M. Kosaka, K. Kondo, K. A. McEwen, J. H. Pixley, and Qimiao Si, "Fieldinduced longrange magnetic order in the spinsinglet ground state system YbAl3C3: Neutron diffraction study", Phys. Rev. B 87, Rapid Commun., 220406(R) (2013).    Emilian M. Nica, Kevin Ingersent, JianXin Zhu, and Qimiao Si, "Quantum critical Kondo destruction in the BoseFermi Kondo model with a local transverse field", Phys. Rev. B 88, 014414 (2013)    J. H. Pixley, Stefan Kirchner, Kevin Ingersent, and Qimiao Si, "Quantum criticality in the pseudogap BoseFermi Anderson and Kondo models: Interplay between fermion and bosoninduced Kondo destruction", Phys. Rev. B 88, 245111 (2013).    M. Yi, D. H. Lu, R. Yu, S. Riggs, J.H. Chu, B. Lv, Z. Liu, M. Lu, Y. Cui, M. Hashimoto, S.K. Mo, Z. Hussain, C. W. Chu, I. R. Fisher, Q. Si, and Z.X. Shen, "Observation of temperatureinduced Crossover to an orbitalselective Mott phase in A(x)Fe(2y)Se2 (A=K, Rb) superconductors", Phys. Rev. Lett. 110, 067003 (2013).    P. Ribeiro, Qimiao Si, and S. Kirchner, "Local quantum criticality out of equilibrium  effective temperature and scaling in the steady state regime", Europhys. Lett. (EPL) 102, 50001 (2013).    Qimiao Si, "Condensed Matter Physics  Hidden is More", Nature 493, N&V, 619620 (2013) http://dx.doi.org/10.1038/493619a    Qimiao Si and Silke Paschen, "Quantum phase transitions in heavy fermion metals and Kondo insulators", Phys. Status Solidi B 250, 425438 (2013). http://dx.doi.org/10.1002/pssb.201300005    Rong Yu and Qimiao Si, "Orbitalselective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K(1x)Fe(2y)Se2", Phys. Rev. Lett. 110, 146402 (2013).    Rong Yu, JianXin Zhu and Qimiao Si, "Orbitaldependent effects of electron correlations in microscopic models for ironbased superconductors", Current Opinion in Solid State and Materials Science 17, 6571 (2013) http://dx.doi.org/10.1016/j.cossms.2013.05.003    Rong Yu, Pallab Goswami, Qimiao Si, Predrag Nikolic, and JianXin Zhu, "Superconductivity at the Border of Electron Localization and Itinerancy", Nature Communications 4, 2783 (2013) http://dx.doi.org/10.1038/ncomms3783    S. Friedemann, S. Paschen, C. Geibel, S. Wirth, F. Steglich, S. Kirchner, E. Abrahams, and Q. Si, "Comment on `Zeemandriven Lifshitz transition: A model for the experimentally observed Fermisurface reconstruction in YbRh2Si2' ", Phys. Rev. Lett. 111, 139701 (2013)    X. Lu, H. Gretarsson, R. Zhang, X. Liu, H. Luo, W. Tian, M. Laver, Z. Yamani, Y.J. Kim, A. H. Nevidomskyy, Qimiao Si, P. Dai, "Avoided quantum criticality and magnetoelastic coupling in BaFe(2x)Ni(x)As2", Phys. Rev. Lett. 110, 257001 (2013).    X.Y. Feng, J. Dai, C.H. Chung, and Qimiao Si, "Competing topological and Kondo insulator phases on a honeycomb lattice", Phys. Rev. Lett. 111, 016402 (2013).    E. Morosan, D. Natelson, Andriy H. Nevidomskyy, and Qimiao Si, "Strongly correlated materials", Advanced Materials 24, 48964923 (2012).    H. Pfau, S. Hartmann, U. Stockert, P. Sun, S. Lausberg, M. Brando, S. Friedemann, C. Krellner, C. Geibel, S. Wirth, S. Kirchner, E. Abrahams, Qimiao Si, F. Steglich, "Thermal and Electrical Transport across a Magnetic Quantum Critical Point", Nature 484, 493497 (2012); doi: 10.1038/nature11072.    J. Custers, K.A. Lorenzer, M. Mueller, A. Prokofiev, A. Sidorenko, H. Winkler, A. M. Strydom, Y. Shimura, T. Sakakibara, R. Yu, Q. Si, and S. Paschen, "Destruction of Kondo effect in cubic heavy fermion compound Ce3Pd20Si6", Nature Materials 11, 189194 (2012); doi:10.1038/nmat3214.    J.H. Pixley, S. Kirchner, K. Ingersent and Qimiao Si, "Kondo destruction and valence fluctuations in an Anderson model", Phys. Rev. Lett. 109, 086403 (2012).    Oliver Stockert, Stefan Kirchner, Frank Steglich, and Qimiao Si, "Superconductivity in Ce and Ubased `122' heavyfermion compounds", J. Phys. Soc. Jpn. 81, 011001 (2012); DOI: 10.1143/JPSJ.81.011001.    Rong Yu and Qimiao Si, "U(1) Slavespin theory and its application to Mott transition in a multiorbital model for iron pnictides", Phys. Rev. B86, 085104 (2012).    Rong Yu, Zhentao Wang, Pallab Goswami, Andriy Nevidomskyy, Qimiao Si, and Elihu Abrahams, "Spin Dynamics of a J1J2K Model for the Paramagnetic Phase of Iron Pnictides", Phys. Rev. B86, 085148 (2012).    S. Nair, S. Wirth, S. Friedemann, F. Steglich, Q. Si and A. J. Schofield, "Hall effect in heavyfermion metals", Adv. Phys. 61, 583664 (2012); http://dx.doi.org/10.1080/00018732.2012.730223.    Stefan Kirchner, Kevin Ingersent, and Qimiao Si, "Quantum criticality of the subohmic spinboson model", Phys. Rev. B85, 075113 (2012); doi: 10.1103/PhysRevB.85.075113.    Elihu Abrahams and Qimiao Si, "Quantum criticality in the iron pnictides and chalcogenides", J. Phys.: Condens. Matter 23, 223201 (2011).    JianXin Zhu, Rong Yu, A. V. Balatsky, and Qimiao Si, "Local Electronic Structure around a Single Impurity as a Test of Pairing Symmetry in (K,Tl)_yFe_xSe2 Superconductors", Phys. Rev. Lett. 107, 167002 (2011).    M. T. Glossop, S. Kirchner, J. H. Pixley, and Qimiao Si, "Critical Kondo destruction in a pseudogap Anderson model: scaling and relaxational dynamics",Phys. Rev. Lett. 107, 076404 (2011)    O. Stockert, J. Arndt, E. Faulhaber, C. Geibel, H. S. Jeevan, S. Kirchner, M. Loewenhaupt, K. Schmalzl, W. Schmidt, Qimiao Si, F. Steglich, "Magnetically driven superconductivity in CeCu2Si2", Nature Physics 7, 119124 (2011).    Pallab Goswami and Qimiao Si, "Effects of Berry phase and instantons in one dimensional KondoHeisenberg model", Phys. Rev. Lett. 107, 126404 (2011).    Pallab Goswami, Rong Yu, Qimiao Si, and Elihu Abrahams, "Spin Dynamics of a J1J2 Antiferromagnet and its Implications for Iron Pnictides", Phys. Rev. B84, 155108 (2011).    Rong Yu and Qimiao Si, "Mott Transition in MultiOrbital Models for Iron Pnictides", Phys. Rev. B84, 235115 (2011).    Rong Yu, JianXin Zhu, Qimiao Si, "Mott transition in Modulated Lattices and Parent Insulator of (K,Tl)_yFe_xSe2 Superconductors", Phys. Rev. Lett. 106, 186401 (2011).    Rong Yu, Pallab Goswami, and Qimiao Si, "The magnetic phase diagram of an extended J1J2 model on a modulated square lattice and its implications for the antiferromagnetic phase of K_yFe_xSe2", Phys. Rev. B84, 094451 (2011).    S. Friedemann, N. Oeschler, S. Wirth, C. Krellner, C. Geibel, F. Steglich, S. Paschen, S. Kirchner, and Qimiao Si, "Discontinuous Hall coefficient at the quantum critical point in YbRh2Si2", J. Phys.: Condens. Matter 23, 094216 (2011).    S. Friedemann, S. Wirth, S. Kirchner, Q. Si, S. Hartmann, C. Krellner, C. Geibel, T. Westerkamp, M. Brando, and F. Steglich, "Break up of heavy fermions at an antiferromagnetic instability", J. Phys. Soc. Jpn. 80, SA002 (2011).    C. de la Cruz, W. Z. Hu, S. Li, Q. Huang, J. W. Lynn, M. A. Green, G. F. Chen, N. L. Wang, H. A. Mook, Qimiao Si, Pengcheng Dai, "Lattice distortion and magnetic quantum phase transitions in CeFeAs(1x)PxO", Phys. Rev. Lett. 104, 017204 (2010).    J.X. Zhu, R. Yu, H. Wang, L. L. Zhao, M. D. Jones, J. Dai, E. Abrahams, E. Morosan, M. Fang, and Qimiao Si,"Band Narrowing and Mott Localization in Iron Oxychalcogenides La2O2Fe2O(Se,S)2'', Phys. Rev. Lett. 104, 216405 (2010).    Nabil Iqbal, Hong Liu, Mark Mezei, and Qimiao Si, "Quantum phase transitions in holographic models of magnetism and superconductors", Phys. Rev. D82, 045002 (2010).    Pallab Goswami, Predrag Nikolic, and Qimiao Si, "Superconductivity in Multiorbital tJ1J2 Model and its Implications for Iron Pnictides", EPL 91, 37006 (2010).    Qimiao Si, "Quantum Criticality and Global Phase Diagram of Magnetic Heavy Fermions", Physica Status Solidi B247, 476484 (2010); http://arxiv.org/abs/arXiv:0912.0040.    Qimiao Si and Frank Steglich, "Heavy Fermions and Quantum Phase Transitions", Science 329, 11611166 (2010).    S. Friedemann, N. Oeschler, S. Wirth, C. Krellner, C. Geibel, F. Steglich, S. Paschen, S. Kirchner, and Qimiao Si, "Fermisurface collapse and quantumdynamical scaling near a quantum critical point", PNAS 107, 1454714551 (2010).    S. Kirchner and Qimiao Si, "On the concept of effective temperature in current carrying quantum critical states", Phys. Status Solidi B247, 631634 (2010).; http://arXiv.org/abs/0909.3925    Seiji J. Yamamoto and Qimiao Si, "Global Phase Diagram of the Kondo Lattice: From Heavy Fermion Metals to Kondo Insulators", J. Low Temp. Phys. 161, 233262 (2010).    Seiji J. Yamamoto and Qimiao Si, "Metallic Ferromagnetism in the Kondo Lattice'', PNAS 107, 1570415707 (2010).
   Seiji Yamamoto and Qimiao Si, "Renormalization Group for Mixed FermionBoson Systems", Phys. Rev. B81, 205106 (2010).    Jianhui Dai, JianXin Zhu, and Qimiao Si, "The fspin physics of rareearth iron pnictides: influence of delectron antiferromagnetic order on heavy fermion phase diagram", Phys. Rev. B 80, 020505(R) (2009).    Jianhui Dai, Qimiao Si, JianXin Zhu, and Elihu Abrahams, "Iron pnictides as a new setting for quantum criticality", PNAS 106, 41184121 (2009)    Qimiao Si, "Iron pnictide superconductors: Electrons on the verge", Nature Physics 5, 629630 (2009).    Qimiao Si, Elihu Abrahams, Jianhui Dai, and JianXin Zhu, "Correlation effects in the iron pnictides", New Journal of Physics 11, 045001 (2009).    Stefan Kirchner and Qimiao Si, "Critical Kondo destruction and the violation of the quantumtoclassical mapping of quantum criticality", Physica B 404, 29042907 (2009).    Stefan Kirchner and Qimiao Si, "Quantum Criticality out of Equilibrium: Steady State in a Magnetic SingleElectron Transistor", Phys. Rev. Lett. 103, 206401 (2009).    Stefan Kirchner, Qimiao Si, and Kevin Ingersent, "Finite Size Scaling of Classical LongRanged Ising Chains and the Criticality of Dissipative Quantum Impurity Models", Phys. Rev. Lett. 102, 166405 (2009).    Jianhui Dai, C. J. Bolech, Qimiao Si, "The BoseFermi Kondo Model in an Exactly Solvable Limit." Physica B, 403 (2008) : 1242.    Philipp Gegenwart, Qimiao Si, and Frank Steglich "Quantum Criticality in Heavy Fermion Metals." Nature Physics (2008) : 186197.    Qimiao Si, Elihu Abrahams "Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides." Physical Review Letters, 101 (2008) : 076401.    Seiji J Yamamoto, Qimiao Si, "Fermi Surface and Magnetism in the Kondo lattice: a Continuum Field Theory Approach." Physica B, 403 (2008) : 1414.    Stefan Kirchner, Qimiao Si "Berry Phase and the Breakdown of the Quantum to Classical Mapping for the Quantum Critical Point of the BoseFermi Kondo model." Physical Review Letters (2008) : arXiv:0808.2647.In Revision    Stefan Kirchner, Qimiao Si "BoseFermi Kondo Model with Ising Anisotropy: ClusterMonte Carlo Approach." Physica B, 403 (2008) : 1199.    Stefan Kirchner, Qimiao Si "Magnetic SingleElectron Transistor as a Tunable Model System for KondoDestroying Quantum Criticality." Physica B, 403 (2008) : 1189.    Stefan Kirchner, Qimiao Si, "Scaling and Enhanced Symmetry at the Quantum Critical Point of the SubOhmic BoseFermi Kondo Model." Physical Review Letters, 100 (2008) : 026403.    J.X. Zhu, S. Kirchner, R. Bulla, and Qimiao Si, "ZeroTemperature Magnetic Transition in an EasyAxis Kondo Lattice Model." Physical Review Letters, 99 (2007) : 227204(14).    Jianhui Dai, Qimiao Si, and C. J. Bolech, "The BoseFermi Kondo Model with a Singular Dissipative Spectrum: Exact Solutions and their Implications." Physical Review Letters: arXiv:0712.3280.Submitted    P. Gegenwart, T. Westerkamp, C. Krellner, Y. Tokiwa, S. Paschen, C. Geibel, F. Steglich, E. Abrahams, and Qimiao Si, "Multiple energy scales at a quantum critical point." Science, 315 (2007) : 969971.    Seiji J. Yamamoto and Qimiao Si, "Fermi surface and antiferromagnetism in the Kondo lattice: an asymptotically exact solution in d>1 dimensions." Physical Review Letters, 99 (2007) : 016401.    JianXin Zhu, A. V. Balatsky, T. P. Devereaux, Qimiao Si, J. Lee, K. McElroy, and J. C. Davis, "FourierTransformed Local Density of States and Tunneling into a dWave Superconductor with Bosonic Modes." Physical Review B, 73 (2006) : 014511.    JianXin Zhu, K. McElroy, J. Lee, T. P. Devereaux, Qimiao Si, J. C. Davis, and A. V. Balatsky, "Effects of Pairing Potential Scattering on FourierTransformed Inelastic Tunneling Spectra in High$T_c$ Cuprate Superconductors with Bosonic Modes." Physical Review Letters, 97 (2006) : 177001.    Qimiao Si, "Global Magnetic Phase Diagram and Local Quantum Criticality in Heavy Fermion Metals." Physica B, 78 (2006) : 2327.    S. D. Wilson, S. Li, P. Dai, W. Bao, JH Chung, H. J. Kang, SH Lee, S. Komiya, Y. Ando, and Qimiao Si, "Evolution of lowenergy spin dynamics in the electrondoped hightransitiontemperature superconductor Pr$_{0.88}$LaCe$_{0.12}$CuO$_{4\delta}$." Physical Review B, 74 (2006) : 144514.    Qimiao Si, JianXin Zhu, and D. R. Grempel "Magnetic Quantum Phase Transitions in Kondo Lattices." J. Phys.: Condens. Matter, 17 (2005) : R10251040.    S. Kirchner, L. Zhu, Q. Si, and D. Natelson "Quantum Criticality in Ferromagnetic SingleElectron Transistors." Proc. Natl. Acad. Sci. USA, 102 (2005) : 1882418829.    S. Kirchner, L. Zhu, and Q. Si "Destruction of the Kondo effect in a multichannel BoseFermi Kondo model." Physica B, 359 (2005) : 8385.    Eugene Pivovarov and Q. Si "Transitions from small to large Fermi momenta in a onedimensional Kondo lattice model." Physical Review B, 69 (2004) : 115104(1)115104(11).    J. Sun, O. Rambow, and Q. Si "Orthogonality Catastrophe in BoseEinstein Condensates." Physical Review Letters (2004) : submitted; condmat/0404590.Submitted    J.X. Zhu, J. Sun, Q. Si, and A. V. Balatsky "Effects of a Collective Spin Resonance Mode on the STM Spectra of DWave Superconductors." Physical Review Letters, 92 (2004) : 017002.    Lijun Zhu, Stefan Kirchner, Qimiao Si, and Antoine Georges "Quantum critical properties of the BoseFermi Kondo Model in a largeN limit." Physical Review Letters, 93 (2004) : 267201.    S. A. Grigera, A. J. Schofield, S. Rabello, and Q. Si "Momentum resolved tunneling in a Luttinger Liquid." Physical Review B, 69 (2004) : 245109(1)245109(8).    S. Paschen, T. Luhmann, S. Wirth, P. Gegenwart, O. Trovarelli, C. Geibel, F. Steglich, P. Coleman, and Q. Si "Halleffect evolution across a heavyfermion quantum critical point." Nature, 432 (2004) : 881885.    Ya. B. Bazaliy, R. Ramazashvili, Q. Si, and M. R. Norman "Magnetotransport near a quantum critical point in a simple metal." Physical Review B, 69 (2004) : 144423(1)144423(11).    Book chapters   Q. Si, "Quantum Criticality and the Kondo Lattice'', Chapter in "Understanding Quantum Phase Transitions'', ed. L. D. Carr (Taylor & Francis, Boca Rato, 2011).    Refereed conference papers   F. Steglich, O. Stockert, S. Wirth, C. Geibel, H. Q. Yuan, S. Kirchner, and Q. Si, "Routes to heavyfermion superconductivity" J. Phys. Conf. Series 449, 012028 (2013). http://dx.doi.org/10.1088/17426596/449/1/012028    Rong Yu, Qimiao Si, Pallab Goswami, and Elihu Abrahams, "Electron Correlation and Spin Dynamics in Iron Pnictides and Chalcogenides", J. Phys.: Conf. Ser. 449, 012025 (2013) http://dx.doi.org/10.1088/17426596/449/1/012025    F. Steglich, J. Arndt, O. Stockert, S. Friedemann, M. Brando, C. Klingner, C. Krellner, C. Geibel, S. Wirth, S. Kirchner and Q. Si, "Magnetism, felectron localization and superconductivity in 122type heavyfermion metals", J. Phys.: Condens. Matter 24, 294201 (2012).    J. H. Pixley, Stefan Kirchner, M. T. Glossop and Qimiao Si, "ContinuousTime Monte Carlo study of the pseudogap BoseFermi Kondo model", J. Phys.: Conf. Ser. 273, 012019 (2011).    Jianda Wu, Lijun Zhu, Qimiao Si, "Entropy accumulation near quantum critical points: effects beyond hyperscaling", J. Phys.: Conf. Ser. 273, 012019 (2011).    Conference papers   Q. Si "Quantum Critical Metals: beyond the Order Parameter Fluctuations." Advances in Solid State Physics, 44 (2004) : 253264.  
Presentations   Invited Talks   “Electron Correlations, BadMetal Behavior and Superconductivity in Iron Pnictides and Chalcogenides”,Frontiers of CMP Workshop, TRIUMF, Vancouver, May 1621, 2015.    “Frustrated Magnetism and Superconductivity in Iron Pnictides and Chalcogenides”,Theoretical and Experimental Magnetism Meeting, Abingdon, UK, July 1617, 2015.    “Frustrated Magnetism and Superconductivity in Iron Pnictides and Chalcogenides”, Joint Workshop on Novel Quantum Matter, Peking University, Beijing, Oct. 15, 2015.    “LocalMoment Magnetism, Quantum Criticality and Heavy Fermion Superconductivity”,Gordon Research Conference on Superconductivity, The Chinese University of Hong Kong, Hong Kong, May 2429, 2015.    “Magnetic Quantum Criticality and Heavy Fermion Superconductivity”, Electronic Structure Approaches and Applications to Quantum Matter, Santa Fe, New Mexico, May 1821, 2015.    “Quantum Criticality and HeavyFermion Superconductivity”, International Workshop on Heavy Fermions and Quantum Phase Transitions, Zhejiang University, Hangzhou, Apr. 1517, 2015.    “Quantum Criticality and Strongly Correlated Electrons”, Condensed Matter Seminar, Renmin University, Beijing, Jan. 7, 2015    “Quantum Criticality and the Kondo Lattice”, International School on Heavy Fermions and Quantum Phase Transitions, Zhejiang University, Hangzhou, Apr. 1214, 2015 (three hours of lectures, part of a threeday school).    “Superconductivity and Electron Correlations in the Iron Pnictides and Chalcogenides”,Center of Advanced Quantum Studies, Beijing Normal University, Beijing, March 12, 2015.    “Superconductivity and Electron Correlations in the Iron Pnictides and Chalcogenides”, National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, China, June 16, 2015.    "Correlated Electrons and Quantum Materials", Physics Colloquium, Zhejiang University, Hangzhou, China, March 21, 2014.    "Electron Correlations and Superconductivity in Iron Pnictides and Chalcogenides", Condensed Matter Seminar, University of California at Berkeley, Sept. 8, 2014.    "Electron Correlations and Superconductivity in Iron Pnictides and Chalcogenides", Physics Institute Seminar, Karlsruhe Institute of Technology, Germany, June 23, 2014.    "Electron Correlations and Superconductivity in the Iron Pnictides and Chalcogenides", Condensed Matter Seminar, University of Toronto, Oct. 3, 2014.    "Electron correlations and Superconductivity in Iron Pnictides and Chalcogenides", Fourth International Conference on Superconductivity and Magnetism (ICSM 2014), Antalya, Turkey, Apr. 27May 2, 2014.    "Electron correlations and Superconductivity in Iron Pnictides and Chalcogenides", The 3rd SuperPIRE REMEI Workshop on Frontiers of Condensed Matter Physics, Beijing, China March 1721, 2014.    "Electron correlations and Superconductivity in Iron Pnictides and Chalcogenides", APS March Meeting, Denver, Colorado, March 37, 2014.    "Electron correlations and Superconductivity in Iron Pnictides and Chalcogenides", 2014 EMN Conference on Iron and Iridiumbased Superconductivity, Cancun, Mexico, June 912, 2014.    "Electron correlations and Superconductivity in Iron Pnictides and Chalcogenides", Beijing International Workshop (II) on Ironbased Superconductors, Institute of Physics, Beijing, China, Aug 47, 2014.    "Electron correlations and superconductivity in the iron based superconductors", ICAM Summer School on New Developments in Condensed Matter Physics, Weihai, China, July 19Aug 6, 2014.    "Local Perspective on NonFermi Liquid, Quantum Criticality and Bad Metals", Aspen Center for Physics 2014 Winter Conference on Condensed MatterBeyond Quasiparticles: New Paradigms for Quantum Fluids, Aspen, Colorado, Jan 1218, 2014.    "Quantum Criticality – How It Works, and How It Elucidates Electronic Matter", Physics Colloquium, University of Toronto, Oct. 2, 2014.    "Quantum Criticality and Emergent Phases in Heavy Fermion Systems", Solid State Physics Colloquium, MaxPlanck Institute for Chemical Physics of Solids, Dresden, Germany, June 5, 2014.    "Quantum Criticality and Emergent Phases in Heavy Fermion Systems", Theoretical and Experimental Magnetism Meeting, Abingdon, UK, July 23, 2014.    "Quantum Criticality and Emergent Phases in Kondo Lattice Systems", Conference on NonFermi Liquids, Stanford University, April 1718, 2014.    "Quantum Criticality, Emergent Phases and Strongly Correlated Electrons", Workshop on Quantum Critical Matter  From Atoms to Bulk, Obergurgl Conference Center, Austria, Aug. 1823, 2014.    "Quantum Criticality, Emergent Phases and Strongly Correlated Electrons", Quantum Materials Perspectives and Opportunities: The Rice Center for Quantum Materials Launch Symposium, Rice University, Houston, Dec. 1516, 2014.    "Superconductivity based on Iron and Beyond: Towards a Conceptual Framework" Black Board Lunch Seminar, KITP, UC Santa Barbara, Nov. 17, 2014.    "Electron Correlations and Superconductivity in Iron Pnictides and Chalcogenides", First CrossStrait Workshop on Novel Quantum Materials, Hualien, Taiwan, Dec. 2428, 2013.    "Electronic Correlations and Quantum Criticality in Iron Pnictides", SinoGerman (International) Workshop on Kondo and Mott Physics in Correlated Matter, Hangzhou, China, Oct. 1417, 2013.    "OrbitalSelective Mott Transition in Iron Pnictide Superconductors", Condensed Matter Science Colloquium, Los Alamos National Lab, Los Alamos, New Mexico, April 3, 2013    "OrbitalSelective Mott Transition in Iron Pnictide Superconductors", Seminar, University of Sherbrooke, Sherbrooke, Canada, April 11, 2013.    "Orbitalselective Correlations and Neutron Resonance Excitations in Iron Pnictide Superconductors", Theoretical and Experimental Magnetism Meeting, Abingdon, UK, July 45, 2013    "Quantum Criticality  from Chilled Antiferromagnets to Charged Black Holes", Physikalisches Kolloquium, Karlsruhe Institute of Technology, Germany, May 10, 2013.    "Quantum Criticality and Emergent Phases in Heavy Fermion Metals", 2013 Hangzhou Workshop on Quantum Matter, Hangzhou, China, April 2225, 2013.    "Quantum Criticality and Strongly Correlated Electrons", Condensed Matter Seminar, University of California at Santa Cruz, Oct. 4, 2013.    "Quantum Criticality and Unconventional Superconductivity", Colloquium, National Lab for Superconductivity, Institute of Physics, Chinese Academy of Sciences, Beijing, China, April 26, 2013.    "Quantum Criticality and its Implications for Heavy Fermion Superconductivity", Spectroscopy on Novel Superconductors (SNS2013), Berkeley, California, June 2428, 2013.    "Quantum Criticality, Emergent Magnetic Phases and Superconductivity", DOECAS HeavyFermion Workshop, Los Alamos National Lab., New Mexico, Nov. 1819, 2013    "Quantum Criticality, Magnetic Frustration and Emergent Phases in Heavy Fermion Metals", International Conference on Strongly Correlated Electron SCES2013, Tokyo, Japan, Aug. 59, 2013.    "Quantum Phase Transitions and Strongly Correlated Electrons", Physics Colloquium, Universite de Montreal, Montreal, Canada, April 12, 2013    "Quantum Phase Transitions in Heavy Fermion Metals and Kondo Insulators", Conference on Quantum Criticality: Experiment and Theory, FreudenstadtLauterbad, Germany, Sept. 1519, 2013.    "Quantum Phase Transitions in Heavy Fermion Metals and Kondo Insulators", Aspen Center for Physics Summer Workshop  Disorder, Dynamics, Frustration and Topology in Quantum Condensed Matter, Aspen, CO, July 9, 2013.    "Superconductivity on the Border of Magnetism: Heavy Fermions and Iron Pnictides", NORDITA Workshop on Superconductivity: the Second Century, Stockholm, Sweden, Aug. 20, 2013.    "Correlated Electrons at the Border of Magnetism", Institute for Basic Science Symposium: From Observation of Quantum States in Solids to Their Control, Seoul, Korea, Sept. 6, 2012.    "Entropy accumulation near quantum critical points", Workshop on Quantum Matter from the Nano to the Macroscale, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany, June 18July 6, 2012.    "Heavy Fermions and Quantum Phase Transitions: A Theorist's Perspective", International Workshop on Heavy Fermions and Quantum Phase Transitions, IOP, Beijing, China, Nov 1012, 2012.    "Local Quantum Criticality and Emergent Phases", Heavy Fermions Physics: Perspectives and Outlook, Beijing, China, Jan 79, 2012.    "Magnetism and orbitalselective Mott physics in iron based superconductors", Theoretical and Experimental Magnetism Meeting, Abingdon, UK, June 2829, 2012.    "OrbitalSelective Mott Transition in Iron Pnictide Superconductors", University College London, London Centre for Nanotechnology, London, UK, May 30, 2012.    "OrbitalSelective Mott Transition in Iron Pnictide Superconductors", Condensed matter seminar, Texas A&M University, College Station, TX, Oct. 5, 2012.    "Quantum Criticality and Emergent Phases in Heavy Fermions", Condensed Matter Colloquium, Los Alamos National Lab, Los Alamos, New Mexico, March 21, 2012.    "Quantum Criticality and Novel Phases", DARPA Workshop on Correlated Quantum Materials, Arlington, VA, Nov. 78, 2012.    "Quantum Criticality and Strongly Correlated Electrons", Colloquium on Solid State Physics, TU Munich, Garching, Germany, Dec. 13, 2012.    "Quantum Criticality, NonFermi Liquid and Unconventional Superconductivity", 19th International Conference on Magnetism (ICM2012), Busan, Korea, July 813, 2012.    "Quantum magnetism of heavy fermions and effects of Berry phase", Workshop on Emergent Phases in Correlated and Topological Matter, Hangzhou, China, April 25, 2012.    "Superconductivity, magnetic interactions and electron correlations in iron pnictides and selenides", Tenth International Conference on Materials and Mechanisms of Superconductivity (M2S 2012), Washington, D.C., USA, July 29Aug. 3, 2012.    "Theory Summary and Perspectives", International Conference on Quantum Criticality and Novel Phases (QCNP12), Dresden, Germany, Aug. 2629, 2012.    "Quantum Criticality and Emergent Phases", Condensed Matter Seminar, Charles University, Praha, Czech Republic, June 1, 2011.    "The new iron chalcogenide (K,Tl)FexSe2: pairing strength and symmetries, and some general lessons about iron pnictides", Theoretical and Experimental Magnetism Meeting, Rutherford Appleton Laboratory, UK, June 1617, 2011.    "Electron Correlations and Superconductivity in Iron Pnictides and Selenides", 26th International Conference on Low Temperature Physics (LT26), Beijing, China, Aug. 1017, 2011.    "Electron Correlations and Superconductivity in Iron Pnictides and Selenides", International Workshop on Electronic Correlations in Models and Materials, Augsburg, Germany, Sept 1115, 2011.    "Electron Correlations and Superconductivity in the Iron Pnictides and Selenides", Condensed Matter Seminar, Harvard University, Cambridge, MA, Oct. 13, 2011.    "Electron Correlations and Superconductivity in the Iron Pnictides and Selenides", Condensed Matter Seminar, UCLA, Los Angeles, CA, Nov. 9, 2011.    "Local quantum criticality, Kondo lattice and holographic models of nonFermi liquids", Black Hole Answers for Condensed Matter Questions, Lorentz center, Leiden, Netherlands, June 16, 2011.    "Quantum Criticality and Emergent Phases", ERC Symposium Quantum Puzzle, Vienna, Austria, June 22, 2011.    "Quantum Criticality and Emergent Phases", Institute Colloquium, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany, April 18, 2011.    "Quantum Criticality and Emergent Phases", Physikalisches Kolloquium, University Bonn, Germany, April 15, 2011.    "Quantum Criticality and Strongly Correlated Electrons", Institute for Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw, Poland, Dec. 8, 2011.    "Quantum Criticality and Strongly Correlated Electrons", Condensed Matter Seminar, University of Michigan, Ann Arbor, Oct. 11, 2011.    "Quantum Criticality and Strongly Correlated Electrons", Chez Pierre Seminar, Massachusetts Institute of Technology, Cambridge, MA, Sept. 26, 2011.    "Quantum Magnetism of Heavy Fermions and Effects of Berry Phases", Condensed matter seminar, Boston College, Boston, MA, Oct. 4, 2011.    "Quantum critical points and emergent phases in heavy fermion metals", Workshop  Developments and Prospects in Quantum Impurity Physics, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany, June 5June 10, 2011.    "Quantum critical points and novel phases in heavy fermion metals", APS March Meeting, Dallas, Texas, March 2125, 2011.    "Quantum criticality and emergent phases in heavy fermion metals", Institute of Physics, Chinese Academy of Sciences, Beijing, China, Aug. 10, 2011.    "The new iron chalcogenide (K,Tl)FexSe2: pairing strength and symmetries, and some general lessons about iron pnictides", International Institute of Physics (IIP) Workshop on Superconductivity, Natal/RN, Brazil, May 1630, 2011.    "Unconventional Superconductivity and Electron Correlations", Aspen Center for Physics Summer Workshop  A New Century of Superconductivity: Iron Pnictides and Beyond, Aspen, CO, June 30, 2011.    "Closing Comments  Theoretical", International Conference on Strongly Correlated Electron SCES 2010, Santa Fe, NM, June 27July 2, 2010.    "Magnetism and Electron Correlations in Iron Pnictides", KITP Miniprogram on IronBased Superconductors, Kavli Institute for Theoretical Physics, UC Santa Barbara, January 1021, 2011.    "Magnetism and Superconductivity in the Iron Pnictides", MaxPlanck Institute for Chemical Physics of Solids, Dresden, Germany, Feb 2, 2010.    "Magnetism, Mott Localization and Superconductivity in Febased Caompounds", Theoretical and Experimental Magnetism Meeting, Institute of Physics, Abingdon, UK, Sept. 89, 2010.    "Quantum Criticality and Global Phase Diagram of Heavy Fermion Metals", 2010 Hangzhou Workshop on Qunatum Matter, Hangzhou, China, May 1821, 2010.    "Quantum Criticality", Discussion Leader, 2010 Gordon Research Conference on Correlated Electron Systems, Mount Holyoke College, South Hadley, MA, June 1318, 2010.    "Quantum Criticality, Kondo Breakdown, and Fermi Surafces", DPG Spring Meeting, Regensburg, Germany, March 2126, 2010.    "Quantum Criticality: ManyBody Systems on the Brink", New Pictures of Strongly Correlated Electron Systems from Large Facilities  Keith McEwen's 65th Birthday Celebration, University College London, June 4, 2010.    "Quantum Phase Transitions and the Border of Magnetism", Physics Colloquium, University of Houston, Houston, Texas, Nov. 9, 2010.    "Theoretical Aspects of the Iron Pnictides", International Conference on Magnetic Materials (ICMM 2010), Saha Institute of Nuclear Physics, Kolkata, India, Oct. 2529, 2010.    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides", APS March Meeting, Pittsburgh, PA, March 1620, 2009.    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides", KITPC Program on Ironbased High Tc Superconductors, Kavli Institute for Theoretical Physics China, Beijing, China, May 18June 5, 2009.    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides", University College London, London Centre for Nanotechnology, London, UK, June 18, 2009.    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides", University of Cambridge, Department of Physics, Cavendish Laboratory, U.K., June 25, 2009.    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides'', University of Tokyo, Department of Applied Physics, Tokyo, Japan, May 20, 2009.    "Fermi Surface and Magnetism in Heavy Fermion Metals", Technical University of Vienna, Austria, June 23, 2009.    "Fermi Surface and Magnetism in Heavy Fermion Metals"; "Electronic Correlations and Magnetic Frustration in the Iron Pnictides" (two talks), Emergent Quantum Phenomena from the Nano to the Macro World, Cargese, Corsica, France, July 619, 2009.    "Iron pnictides as a new setting for quantum criticality", MaxPlanck Institute for Chemical Physics of Solids, Dresden, Germany, April 2, 2009.    "Magnetism and Superconductivity in the Iron Pnictides", CCAST Workshop on Iron Based Superconductors, Beijing, China, Dec 56, 2009.    "Magnetism and Superconductivity in the Iron Pnictides'', Kyoto University, Kyoto, Japan, Dec 10, 2009.    "Magnetism and Superconductivity in the Iron Pnictides'', T4 Seminar, Los Alamos National Lab, Los Alamos, New Mexico, Nov. 12, 2009.    "Magnetism and Superconductivity in the Iron Pnictides", Theoretical and Experimental Magnetism Meeting, Institute of Physics, Abingdon, UK, July 23, 2009.    "Quantum Criticality in Heavy Fermion Metals'', Condensed matter seminar, Texas A&M University, College Station, TX, Oct. 2, 2009.    "Quantum Criticality out of Equilibrium", KITP Program on Low Dimensional Electron Systems, KITP, UC Santa Barbara, May 7, 2009.    "Quantum Criticality, Kondo Effect, and Fermi Surfaces", University of Tokyo, Institute for Solid State Physics, Tokyo, Kashiwa, Chiba, May 19, 2009.    "Quantum ManyBody Physics and Strongly Correlated Electron Systems'', Physics Colloquium, Beihang University, Beijing, China, Dec 8, 2009.    "Superconductivity in the Iron Age'', Colloquium, Department of Physics and Astronomy, Rice University, Houston, TX, Sept. 2, 2009.    "Theoretical Overview", Aspen Center for Physics Summer Workshop on Correlated Behavior and Quantum Criticality in Heavy Fermion and related Systems, Aspen, CO, August 11, 2009.    "Towards a Global Phase Diagram of Magnetic Heavy Fermions", Hangzhou Workshop on Quantum Matter, Hangzhou, China, Oct. 1215, 2009.    "What is Going on in the Iron Pnictides", TcSUH, University of Houston, April 9, 2009.    "Are Iron Pnictides Strongly Correlated." Aspen Center for Physics Summer Workshop on Frontiers of Strongly Correlated Electrons, Aspen, CO. (Aug 7, 2008)    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides." Condensed matter seminar, Iowa State University, Ames, Iowa. (Sept 25, 2008)    "Electronic Correlations and Magnetic Frustration in the Iron Pnictides." Beijing International Workshop on Iron(Nickel)based Superconductors, Institute of Physics, Chinese Academy of Sciences, Beijing, China. (Oct 1719, 2008)    "Fermi Surface and Magnetism in Kondo Lattice Systems." Workshop on Unconventional Phases and Phase Transitions in Strongly Correlated Electron Systems, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany. (June 227, 2008)    "Fermi Surface and Magnetism in the Kondo Lattice." 2008 Gordon Research Conference on Correlated Electron Systems, New Biddeford, Maine. (June 813, 2008)    "Magnetism and Quantum Criticality in Heavy Fermions and Iron Pnictides." ICAM/DCHEM Workshop on Emergent Behavior in Heavy Electron Materials, Aspen, CO. (Aug 28, 2008)    "Magnetism in Heavy Fermions and Iron Pnictides." Theoretical and Experimental Magnetism Meeting, Institute of Physics, Abingdon, UK. (July 31August 1, 2008)    "Quantum Criticality beyond OrderParameter Fluctuations." Aspen Center for Physics 2008 Winter Conference on Condensed Matter: New Horizons in Condensed matter Physics, Aspen, CO. (Feb 39, 2008)    "Strongly Correlated Electron Systems." Second International Vienna Symposium on Functional Matter: From designer materials to quantum technologies, TUWien, Austria. (June 27, 2008)    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." Institute of Physics, CAS, Beijing, China. (May 19, 2008)    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." University of Science and Technology of China, Hefei, China. (April 29, 2008)    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." Physics Colloquium, Zhejiang University, Hangzhou,China. (May 6, 2008)    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." Fudan University, Shanghai, China. (May 8, 2008)    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." Center for Advanced Studies, Tsinghua University, Beijing, China. (May 15, 2008)    "Summary Discussion." ICAM Workshop on Fepnictide and Related Superconductors, College Park, Maryland. (Nov 1617, 2008)    "Fermi Surface and Antiferromagnetism in Kondo Lattice Systems." MaxPlanck Institute for Chemical Physics of Solids, Dresden, Germany. (Feb 12, 2007)    "Heavy fermion quantum criticality: Fermi surface and multiple energy scales." Frontiers of Condensed Matter  Celebrating the research achievements of Elihu Abrahams, Rutgers University, Piscataway, NJ. (April 2022, 2007)    "Local Quantum Criticality: from Heavy Fermions to Magnetic Nanostructures." New Frontiers in Quantum Impurity Physics: From NanoStructures to Molecular Devices, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany. (August 1324, 2007)    "Local Quantum Criticality: from Heavy Fermions to Nanodevices." NHMFL, Florida State University, Tallahassee, Florida. (Sept 26, 2007)    "Local Quantum Criticality: from Heavy Fermions to Nanostructures." Physics Colloquium, Zhejiang University, Hangzhou, China. (July 2, 2007)    "Quantum Criticality and Fermi Surfaces." KITP Program on Strongly Correlated Phases in Condensed Matter and Degenerate Atomic Systems, KITP, UC Santa Barbara, CA. (April 12, 2007)    "Quantum Criticality and Fermi Surfaces." KITPC Program on Quantum Phases of Matter, Kavli Institute for Theoretical Physics China, Beijing, China. (July 6, 2007)    "Quantum Criticality and Strongly Correlated Electrons." Condensed Matter Colloquium, Los Alamos National Lab, Los Alamos, NM. (Oct 3, 2007)    "Quantum Criticality and Superconductivity in Heavy Fermions." Aspen Center for Physics Summer Workshop on Novel Aspects of Superconductivity, Aspen, CO. (July 21, 2007)    "Quantum Criticality in Correlated Matter." Physics Colloqium, Dartmouth College, Hanover, New Hampshire. (Jan 26, 2007)    "Quantum Criticality in Kondo Lattices." ICAM Workshop on 115 Materials: The Rosetta Stone for the Kondo Lattice, Aspen, CO. (Aug 4, 2007)    "Quantum Criticality of Heavy Fermion Metals: Thermodynamic Aspects." National High Magnetic Field Lab, Tallahassee, Florida. (Sept. 27, 2007)    "Quantum Criticality, Kondo Effect and Fermi Surfaces." Homage to Daniel Grempel Memorial Conference, CEASaclay, France. (June 1415, 2007)    "Quantum Fluctuations, Criticality, and Strongly Correlated Electrons." Workshop on Future Directions in Interacting Electron Physics, Austin, Texas. (Octt 11, 2007)    "Quantum Phases and their Transitions in Magnetic Heavy Fermions." The Heavy Fermion Frontier: a Workshop in Honor of Joe D. Thompson's 60th Birthday, Santa Fe, New Mexico. (Nov 12, 2007)    "Global Phase Diagram and Quantum Criticality in Magnetic Heavy Fermion Metals." International Conference on Magnetism (ICM2006), Kyoto, Japan. (Aug 2025, 2006)    "Quantum Critical Point beyond OrderParameter Fluctuations  the Case of Heavy Fermion Metals." Condensed Matter Seminar, University of California at Riverside, Riverside, CA. (April 12, 2006)    "Quantum Criticality." Hangzhou Workshop on Quantum Matter, Hangzhou, China. (Oct 1619, 2006)    "Quantum Criticality." Condensed Matter Seminar, University of Virginia, Charlottesville, Virginia. (Sept 28, 2006)    "Quantum Criticality and FermiSurface Transformation." Eighth International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors (M2SVIII), Dresden, Germany. (July 914, 2006)    "Quantum Phase Transition and nonFermi Liquid Behavior." International Conference on Physics Education and Frontier Physics, Taipei, Taiwan. (June 2730, 2006)    "Quantum Phase Transitions and Strongly Correlated Electrons." Physics Colloquium, University of Science and Technology of China, Hefei, China. (July 3, 2006)    "Local Quantum Criticality and FermiSurface Transformation." Theoretical and Experimental Magnetism Meeting, Institute of Physics and ISIS/CCLRC, Abingdon, UK. (August 23, 2005)    "Phenomenological Aspects of Local Quantum Criticality." Fifth International Symposium on Advanced Science Research Advances in the Physics and Chemistry of Actinide Compounds, JAERI Tokai, Ibaraki, Japan (cancelled due to Hurricane Rita). (Sept. 2729, 2005)    "Quantum Criticality in Kondo Systems." Aspen Center for Physics Summer Workshop on Gauge Theories and Fractionalization in Correlated Quantum Matter, Aspen, CO. (August 9, 2005)    "Quantum Phase Transition and nonFermi Liquid Behavior." Conference on Physical Phenomena at High Magnetic FieldsV, National High Magnetic Field Laboratory, Tallahassee, Florida. (August 59, 2005)    "Quantum Phase Transitions and Correlated Electrons." University College London, London, UK. (March 10, 2005)    "Quantum Phase Transitions and Strongly Correlated Electrons." PHYSICS COLLOQUIUM, Zhejiang University, Hangzhou, China. (Dec. 9, 2005)    "Quantum Phase Transitions and Strongly Correlated Electrons." I2CAM Workshop on Chemical Physics of Complex Adaptive Matter, Ringberg Castle (Bavaria), Germany. (February 6  9, 2005)    "The Global Phase Diagram of Magnetic Heavy Fermion Metals." Joint Workshop of NQP (New Quantum Phenomena)skutterudites and NPM (New Phase of Matter) in multiapproach, Tokyo Metropolitan University, Hachioji, Tokyo. (November 21 24, 2005)    "Two talks: 1) Kondo lattices: What do we learn from microscopics? 2) Heavy fermion metals: Global phase diagram, local quantum criticality, and experiments." Workshop on Emergent Quantum Phases in Strongly Correlated Electron Systems, Korea Institute for Advanced Study (KIAS), Seoul, Korea. (October 2429, 2005)    "Exotic Quantum Criticality in Kondo Lattices." KITP Program on Exotic Order and Criticality in Quantum Matter, KITP, UCSB. (June 30, 2004)    "Extended DMFT Study of Kondo Lattices." Workshop on Quantum Criticality and Dynamical Mean Field Theory, SPhT/CEASaclay, France. (Dec 7, 2004)    "Hall Effect and Fermi Surface Fluctuations near Quantum Critical Points." Theory Seminar, University of karlsruhe, Karlsruhe, Germany. (Feb, 2004)    "Local Quantum Critical Points: from Correlated Matters to Mesoscopic Structures." Condensed Matter Seminar, University of Sherbrooke, Sherbrooke, Canana. (March, 2004)    "Local Quantum Criticality and Fermisurface Fluctuations." International Workshop on Materials Science and NanoEngineering, Osaka, Japan. (Dec 1014, 2004)    "Local Quantum Criticality and nonFermi Liquid Properties." ICTP Workshop on Novel States and Phase Transitions in Highly Correlated Matter, Trieste, Italy. (July 1223, 2004)    "Local Quantum Criticality and nonFermi Liquid Properties." American Physical Society March Meeting, Montreal, Quebec, Canada. (March 2226, 2004)    "Local Quantum Criticality and nonFermi Liquid Properties." DPG (Germany Physical Society) Spring Meeting, Regensburg, Germany. (March 812, 2004)    "Quantum Critical Metals: beyond Order Parameter Fluctuations." International Workshop on Evolution of Quantum Effects from the Nanoto the Macroscale, Cargese, Corsica, France. (May 1722, 2004)    "Quantum Criticality in Kondo Systems." YKIS 2004 Physics of Strongly Correlated Electron Systems, Yukawa Institute, Kyoto, Japan. (Nov 1219, 2004)    "Quantum Phase Transitions and nonFermi Liquid Phenomena." WEHeraeusSeminar on Quantum Phase Transitions, Bad Honnef, Germany. (October 1014, 2004)    "Quantum Phase Transitions in Kondo Impurities and
in Mesoscopic Structures." Condensed Matter Seminar, Cologne University. (Oct 8, 2004)    "TURNING UP THE HEAT AT ZERO TEMPERATURE: Quantum Phase Transitions and nonFermi Liquids." Physics Colloquium, Rice University. (Nov 10, 2004)    "TURNING UP THE HEAT AT ZERO TEMPERATURE: Quantum Phase Transitions and nonFermi Liquids." Physics Colloquium, Louisiana State University. (Oct 28, 2004)    Keynote Speaker   "Quantum Criticality and Strongly Correlated Electrons", 27th International Conference on Low Temperature Physics (LT27), SemiPLENARY TALK, Buenos Aires, Argentina, Aug. 613, 2014.    "Magnetism in metals on the verge of Mott transition and quantum criticality in parent pnictides", Keynote Speaker, SEPnet Summer Program: Condensed Matter Physics in the City, London, UK, June 1314, 2011.    "Quantum Criticality, Kondo Breakdown, and Fermi Surfaces", PLENARY TALK, International Conference on Quantum Criticality and Novel Phases (QCNP09), Dresden, Germany, Aug. 25, 2009.    "Quantum Criticality and Fermi Surface Transformation." PLENARY TALK, International Conference on Strongly Correlated Electron SCES'05, Vienna, Austria. (July 26  30, 2005)    Lectures   "Quantum Criticality and Heavy Fermion Physics", ColumbiaRice Frontiers of Condensed Matter Physics Lecture Series, Rice University, Houston, Oct. 22 and 24, 2013 (two lectures).    "Quantum Criticality and Strongly Correlated Fermions", Bethe Colloquium, University Bonn, Germany, May 6, 2013.    "Quantum Criticality and The Kondo Lattice", Second Fudan Summer School for Condensed Matter Physics  Quantum Phase Transitions, July 1922, 2012 (summer school lectures, 4 days, 8 hrs).    "Kondo Problem to Heavy Fermions and Local Quantum Criticality", Advanced School  Developments and Prospects in Quantum Impurity Physics, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany, May 30June 3, 2011.    "Magnetism, Localization and Superconductivity", Inaugural Lecture of Changhiang Professorship, Zhejiang University, Hangzhou, China, Oct. 22, 2010.    "Quantum Criticality and Heavy Fermions", Tutorial lecture, PostWorkshop Tutorial 2010 Hangzhou Workshop on Qunatum Matter, Hangzhou, China, May 22, 2010.    "Strongly Correlated Electrons: from Quantum Criticality to the High Tc Iron Pnictides." Frontiers in Chemical Physics of Solids Lecture, MaxPlanck Institute for Physics of Complex Systems, Dresden, Germany. (June 19, 2008)  
Editorial Positions   Member of the Editorial Board, Journal of Physics: Condensed Matters. IOP. (2002  2006)

Supervised Theses & Dissertations   Seiji J Yamamoto, Ph.D Magnetism and Fermi Surface in Heavy Fermion Metals. (2009) (Thesis or Dissertation Director)
  Jianda Wu, Ph.D. "Research on Dynamics and Thermodynamics near Quantum Critical Points. (2014) (Thesis or Dissertation Director)
  Aditia Shashi, Ph.D. Exploring aspects of nonequilibrium physics with quantum impurity problems. (2014) (CoDirector)
  Jed Pixley, Ph.D. Quantum Criticality in Heavy Fermion Metals and a New Route to Superconductivity. (2014) (Thesis or Dissertation Director)
  Tal Einav, B.S. Iron pnictides superconductivity. (Thesis or Dissertation Director)

Awards, Prizes, & Fellowships   Humboldt Prize, Alexander von Humboldt Foundation (20132014)
  Bethe Colloquium, University of Bonn, Germany (May 2013)
  Qianren Short Term Visiting Professor, Institute of Physics, Chinese Academy of Sciences (20122015)
  Changjiang Chair Professor, China's Ministry of Education (20102012),
  Fellow, American Association for the Advancement of Science (since 2008),
  Frontiers in Chemical Physics of Solids Lecture (MaxPlanck InstituteCPfS, 2008), MaxPlanck Institute  CPfS, Dresden, Germany (2008)
  CoChairman, SCES'07 (2007 International Conference on Strongly Correlated Electron Systems), Houston, May 2007, (May, 2007)
  Fellow, American Physical Society (since 2005), (2005)
  Fellow, Institute of Physics, UK (since 2004),
  Alfred P. Sloan Research Fellow, (9600)
  Cottrell Scholar Award, Research Corporation (9803)

Positions Held   General Member, Aspen Center for Physics, Aspen Center for Physics. (2009  2019)
  Corresponding Member (since 2011), Journal Club for Condensed Matter Physics. (2011  2016)
  Director, Rice Center for Quantum Materials (since 2014). (2014  2016)
  Humboldt Research Award Visiting Professor, Karlsruhe Institute of Technology. (2013  2014)
  Visiting Associate Professor, Dept of Physics, University of Illinois at UrbanaChampaign. (2002  2002)

