Sung-Sik Lee

Research Interests

Condensed matter systems, that include insulators, semiconductors, metals and superconductors among many others, consist of many particles, of the order of ten to the twenty three. At the microscopic level, the dynamics of individual particles is governed by the well established theoretical framework, quantum mechanics. However, it is extremely difficult to understand and predict macroscopic behaviors of a whole system, starting from the microscopic theory. For the past 30 years, it has become clear that understanding macroscopic properties is not a matter of mere application of the known physical laws. Instead, collective behaviors are governed by novel organizing principles, which are not manifest from the microscopic rule of dynamics. Currently, the primary goal of my research is to identify new dynamical principles that are behind novel emergent phenomena in gapless phases of matter such as unconventional metals and systems near quantum critical points, and to apply those principles to understand physical properties observed in experiments. To achieve the goal, I use various theoretical tools, including quantum many-body theory and quantum field theory. I am also interested in the interdisciplinary research areas between condensed matter physics, string theory and gravitational theory. Recently I have been developing the notion of `quantum renormalization group' where coupling constants are promoted to quantum mechanical operators to make a connection between general D-dimensional quantum many-body systems and (D+1)-dimensional quantum theory of gravity via holography. I am trying to use the quantum renormalization group scheme to understand strongly coupled field theories that are hard to solve otherwise.

Positions Held

• July 2012 - present : Department of Physics and Astronomy, McMaster University, Associate Professor
• July 2007 - June 2012 : Department of Physics and Astronomy, McMaster University, Assistant Professor
• July 2006 --- June 2007 : Post doctoral researcher, Kavli Institute for Theoretical Physics, Santa Barbara
• Mar. 2004 --- Jul. 2006 : Post doctoral researcher, Massachusetts Institute of Technology
• Nov. 2002 --- Feb. 2004: Post doctoral researcher, Pohang University of Science and Technology

Awards

• Early Research Award, $100,000 for five years, Ontario Ministry of Research and Innovation

Recent Publications

• Q. Hu, S.-S. Lee, ``Non-local Geometry inside Lifshitz Horizon", JHEP 07 (2017) 56, arXiv: 1703.07522.
• P. Lunts, A. Schlief, S.-S. Lee, ``Emergence of a control parameter for the antiferromagnetic quantum critical metal", Phys. Rev. B 95, 245109 (2017), arXiv: 1701.08218.
• A. Schlief, P. Lunts, S.-S. Lee, ``Exact critical exponents for the antiferromagnetic quantum critical metal in two dimensions'', Phys. Rev. X 7, 021010 (2017), arXiv: 1608.06927.
• S. Sur and S.-S. Lee, ``Anisotropic Non-Fermi Liquids", Phys. Rev. B 94, 195135 (2016), arXiv: 1606.06694.
• S.-S. Lee, ``Horizon as Critical Phenomenon'', JHEP (2016) 2016: 44, arXiv: 1603.08509.
• P. Lunts, S. Bhattacharjee, J. Miller, E. Schnetter, Y. B. Kim, S.-S. Lee, "Ab initio holography", JHEP 08 (2015) 107, arXiv: 1503.06474
• S. Ghamari, S.-S. Lee and C. Kallin, ``RG Analysis on a Neck-Narrowing Lifshitz Transition in the Presence of Weak Short-Range Interactions in Two Dimensions", Phys. Rev. B 92, 085112 (2015) , arXiv: 1407.6732.
• I. Mandal and S.-S. Lee, ``UV/IR mixing in Non-Fermi Liquids", Phys. Rev. B 92, 035141 (2015), arXiv: 1407.0033.
• S. Sur and S.-S. Lee, "Quasi-Local Strange Metal", Phys. Rev. B 91, 125136 (2015), arXiv: 1405.7357.
• S. Sur and S.-S. Lee, ``Chiral non-Fermi liquids", Phys. Rev. B 90, 045121 (2014), arXiv: 1310.7543
• Sung-Sik Lee, "Quantum Renormalization Group and Holography", JHEP 01, 076 (2014), arXiv: 1305.3908.
• P. Ponte and S.-S. Lee, ``Emergence of supersymmetry on the surface of three dimensional topological insulators'', New J. Phys. 16, 013044 (2014), arXiv : 1206.2340
• Denis Dalidovich and Sung-Sik Lee, "Perturbative non-Fermi liquids from dimensional regularization", Phys. Rev. B 88, 245106 (2013), arXiv: 1307.3170
• Marlon Rodney, H. Francis Song, Sung-Sik Lee, Karyn Le Hur, Erik Sorensen, "Scaling of entanglement entropy across Lifshitz transitions", Phys. Rev. B 87, 115132 (2013)
• Sung-Sik Lee, "Background independent holographic description : From matrix field theory to quantum gravity", JHEP 1210 (2012) 160
• S.-S. Lee, ``Holographic Matter : Deconfined String at Criticality'', Nucl. Phys. B 862, 781 (2012), arXiv: 1108.2253.
• S. Bhattacharjee, S.-S. Lee and Y. B. Kim, ``Spin-Orbital Locking, Emergent Pseudo-Spin, and Magnetic order in Na2IrO3'', New J. Phys.14, 073015 (2012), arXiv: 1108.1806.
• S. Bhattacharjee, Y. B. Kim, S.-S. Lee, and D.-H. Lee, ``Fractionalized topological insulators from frustrated spin models in three dimensions'', Phys. Rev. B 85, 224428 (2012), arXiv: 1202.0291.
• S. Ghamari, C. Kallin, S.-S. Lee, and E. S. Sorensen, ``Order in a Spatially Anisotropic Triangular Antiferromagnet'', Phys. Rev. B 84, 174415 (2011), arXiv : 1108.3036.
• S.-S. Lee, ``Holographic description of large N gauge theory'', Nucl. Phys. B 851, 143 (2011), arXiv: 1011.1474.
• A. Bayntun, C.P. Burgess, Brian P. Dolan, S.-S. Lee, AdS/QHE: Towards a Holographic Description of Quantum Hall Experiments, New J.Phys.13:035012 (2011), arXiv: 1008.1917.
• S.-S. Lee, ``Recent Developments in Non-Fermi Liquid Theory'', to appear in Annual Review in Condensed Matter Physics, arXiv: 1703.08172

Seminars

• "Exact critical exponents for the antiferromagnetic quantum critical metal in two dimensions", Summer Workshop on Quantum Criticality in Metallic Systems, Aspen, August 2017
• "Exact critical exponents for the antiferromagnetic quantum critical metal in two dimensions", Conference on Order, Fluctuations, and Strong Correlations: New Platforms and Developments, KITP, Santa Barbara, July 2017
• "Quantum Renormalization Group", Theory Canada, York University, May 2017
• "Exact critical exponents for the antiferromagnetic quantum critical metal in two dimensions", Quantum Materials Symposium, Muju, Korea, February 2017
• "Exact critical exponents for the antiferromagnetic quantum critical metal in two dimensions", Workshop on many-body entanglement and strongly correlated phenomena, Sanya, China, December. 2016
• "Horizon as critical phenomenon", Journey to the center of the bulk, Princeton Center for Theoretical Science, Princeton, October 2016
• "Low-energy effective theories for non-Fermi liquids", Rutgers University, September, 2016
• "Quantum renormalization group and holography", Lecture Series on Beyond Landau Fermi liquid and BCS superconductivity near quantum criticality and Real space renormalization group approach, APCTP, Pohang, June 2016
• "Horizon as critical phenomenon", Workshop on Emergent properties of space-time, CERN, Switzerland, June 2016
• "Horizon as dynamical quantum phase transition", Conference on holography and quantum information, Yukawa Institute for theoretical physics, Japan, June, 2016
• "Low energy effective theories for non-Fermi liquids", Lecture Series on Beyond Landau Fermi liquid and BCS superconductivity near quantum criticality and Real space renormalization group approach, APCTP, Pohang, June 2016
• "Low energy effective theories for metals", CIFAR Summer School, Toronto, April 2016
• "Quantum renormalization group", CIFAR Summer School, Toronto, April 2016
• "Quantum RG, tensor network and holography", Gauge/Gravity Duality and Condensed Matter Physics, Banff International Research Station, February 2016
• "Ab Inition Holography", Columbia University, Nov. 2015
• "Ab Inition Holography", University of Florida, Tallahasse, Oct. 2015
• "Ab Inition Holography", Brock University, Oct. 2015
• "Ab-Initio Holograph", International Workshop on Strings, Black Holes and Quantum Information, Tohoku University, Japan, September 2015
• "Ab-Initio Holograph", Beyond Quasiparticle, Aspen Center for Physics, August 2015
• "Quantum Renormalization Group", International Congress on Mathematical Physics, Santiago, Chile, July 2015
• "Ab-Initio Holograph", Entanglement in Strongly Correlated Quantum Matter, KITP, Santa Barbara, June 2015
• "Quasi-Local strange metal", POSTECH, Pohang, Korea, April 2015
• "Low energy effective theories for non-Fermi liquids", Pioneering symposium on Quantum Criticality and Emergent Phenomena, Daejeon, Korea, April 2015
• "Quasi-Local strange metal", Symposium on Quantum Criticality : Heavy Fermion Systems and Beyond, Rice University, Houston, March 2015
• "Ab-Initio Holograph", Simons Symposium on Quantum Entanglement, Puerto Rico, March 2015
• "Quasi-Local strange metal", Quantum Material Symposium, Muju, Korea, Feb. 2015
• "Ab-Initio Holograph", Workshop on Holographic Renormalization Group and Entanglement, Paris, January, 2015
• "Ab Inition Holography", University of Chicago, Dec. 2014
• "Low energy effective theories for non-Fermi liquids", Conference on Quantum Field theory, String Theory and Condensed Matter Physics, Orthodox Academy of Crete, September 2014
• "Low energy effective theories for non-Fermi liquids", 2014 IASTU summer forum on topology and strong correlation in condensed matter physics, Tsinghua university, June, 2014
• "Quasi-local strange metal", 2014 IASTU summer forum on topology and strong correlation in condensed matter physics, Tsinghua university, June, 2014
• "Quasi-local strange metal", Workshop on non-Fermi liquids, SITP, Stanford University, April 2014
• "Low energy effective theories for non-Fermi liquids", Condensed matter seminar, University of Illinois Urbana Champaign, March 2014
• "Quantum renormalization group and Holography", Physics of Emergence, University of Pittsburgh, Feb. 2014
• "Low energy effective theories for non-Fermi liquids", Beyond quasiparticle : New paradigm for quantum fluids, Aspen Center for Physics, Jan. 2014
• "Quantum renormalization group and AdS/CFT", String Seminar, Stanford, Nov. 2013
• "Low energy effective theories for non-Fermi liquids", Condensed matter seminar, Stanford, Nov. 2013
• "Low energy effective theories for non-Fermi liquids", Condensed matter seminar, MIT, Nov. 2013
• "Low energy effective theories for non-Fermi liquids", Condensed matter seminar, Harvard, Nov. 2013
• "Quantum renormalization group and Holography", Holography : from gravity to quantum matter, Issac Newton Institute, Cambridge, United Kingdom, Sept. 2013
• "Low energy effective theories for non-Fermi liquids in two dimensions", Bad metal behavior and Mott quantum criticality, APCTP, Pohang, Korea, July 2013
• "Quantum renormalization group and Holography", Workshop and Conference on Geometrical Aspects of Quantum States in Condensed Matter, ICTP, Trieste, Italy, July 2013
• "Quantum renormalization group and AdS/CFT", String Seminar, Caltech, April 2013
• "Quantum renormalization group and AdS/CFT", String Seminar, University of Michigan, Ann Abor, March 2013
• "Quantum renormalization group and AdS/CFT", Simons Symposium on Quantum Entanglement, Caneel Bay, St. John, Feb. 2013
• "From renormalization group to emergent gravity: holographic description of quantum many-body matter", String Seminar, MIT, Nov. 2012
• "Emergent phenomena in condensed matter systems", Colloquium, Virginia Tech, Nov. 2012
• "From renormalization group to emergent gravity: holographic description of quantum many-body matter", Topology, Entanglement and Strong Correlations in Condensed Matter, University of Urbana Champaign, Nov. 2012
• "From Renormalization Group to Emergent Gravity: Holographic Description of Quantum Many-body Systems", KITP Conference: Exotic Phases of Frustrated Magnets, KITP, Santa Barbara, Oct. 2012
• "Chiral non-Fermi liquids in two dimensions", Center for Quantum Materials Inaugural conference, Field Institute, Toronto, Sep. 2012
• "From renormalization group to emergent gravity: holographic description of quantum many-body systems", ICTP2012: Innovations in Strongly Correlated Electronic Systems, ICTP, Trieste, Italy, August 2012
• ``Non-Fermi liquids in two dimensions'', 2012 Canadian Association of Physicists Congress, Alberta, June 2012
• ``Quantum field theory and quantum gravity'', Theoretical Physics Workshop, University of Western Ontario, April 2012
• ``Emergent dimension and quantum critical point'', APS March meeting, Boston, March 2012
• ``Holographic matter; deconfined string at criticality", SPOCK meeting, University of Cincinnati, December 2011
• ``Holographic matter; deconfined string at criticality'', String Seminar, University of California, Berkeley, Nov. 2011
• ``Connections between new states of condensed matter and string'', Origins Colloquium, Origin Institute, McMaster University, Oct. 2011
• ``Holographic matter; deconfined string at criticality", Holographic Duality and Condensed Matter Physics, KITP, Santa Barbara, USA, September 2011
• ``Holographic matter; deconfined string at criticality", KIAS-YITP Joint Workshop on String Theory, Holography and Beyond, Seoul, Korea, September 2011
• ``Holographic matter; deconfined string at criticality", Conference on Cold Materials, Hot Nuclei, and Black Holes: Applied Gauge/Gravity Duality, ICTP, Trieste, Italy, August 2011
• ``Holographic Matter'', Workshop on Emergence in Field Theory, IAS, Nanyang Technological University, Singapore, Aug 2011
• PIRSA:16120009, Low energy field theories for non-Fermi liquids, 2016-12-07, Colloquium
• PIRSA:15110066, Welcome and Opening Remarks, 2015-11-05, PI-UIUC Joint Workshop on Strongly Correlated Quantum Many-Body Systems 2015
• PIRSA:15070061, Anisotropic Non-Fermi Liquids , 2015-07-10, Recent Progress on High Tc Superconductivity and Related Problems
• PIRSA:15040162, Low energy field theories for non-Fermi liquids, 2015-04-30, 4 Corners Southwest Ontario Condensed Matter Physics Symposium 2015
• PIRSA:14010100, Low energy effective theories for non-Fermi liquids, 2014-01-10, Condensed Matter Group Meeting
• PIRSA:13050036, Quantum renormalization group and AdS/CFT, 2013-05-08, Emergence & Entanglement II 2013
• PIRSA:12060028, TBA, 2012-06-08, Exploring AdS/CFT Dualities in Dynamical Settings
• PIRSA:12050033, Background Independent Holographic Description : From Matrix Field Theory to Quantum Gravity, 2012-05-22, String Seminars
• PIRSA:11100095, First Principle Construction of Holographic Duals , 2011-10-25, Tensor Networks for Quantum Field Theories Conference
• PIRSA:11100057, Quantum Order and Emergent Space in Holographic Phases of Matter, 2011-10-18, String Seminars
• PIRSA:10070001, Holographic description of quantum field theory, 2010-07-20, String Seminars
• PIRSA:10050087, Holographic description of quantum field theory, 2010-05-29, Emergence and Entanglement
• PIRSA:08120018, Emergent supersymmetry and holographic non-Fermi liquid , 2008-12-03, String Seminars
• PIRSA:07040033, Spin Liquid with Spinon Fermi Surface: Its Stability and Possible Application to the Organics, 2008-04-24, Southwestern Ontario 4-Corner Condensed Matter Symposium
• PIRSA:06030004, Dual gravity study of the (2+1)D compact U(1) gauge theory coupled with strongly interacting matter fields, 2006-03-06, Colloquium