Center for Correlated Electron Systems

Theory Group

Correlated Quantum Matter Theory

Our research group studies a broad class of theoretical problems about correlated topological quantum matter by using various theoretical tools including analytic quantum field theory and numerical methods. Currently, we are focusing on new emergent quantum physics originating from the nontrivial interplay between electron correlations and bulk topological properties such as quantum critical phenomena in topological media, interacting Weyl/Dirac semimetals, 5d transition metal oxides, frustrated quantum magnets, etc. Our aim is to search for unconventional quantum states of matter beyond the conventional paradigms and theoretically design novel functional materials.
Prof. Bohm-Jung Yang's photo
Selected Publications
Large anomalous Hall current induced by topological nodal lines in a ferromagnetic van der Waals semimetal
Nature materials 17 , 1476-4660 (2018)
Unconventional topological phase transition in two-dimensional systems with space-time inversion symmetry
Physical Review Letters 118 , 156401 (2017)
Emergent non-Fermi liquids at the quantum critical point of a topological phase transition in two dimensions
Physical Review Letters 116 , 076803 (2016)
Magnetic-field-induced insulator-semimetal transition in a pyrochlore Nd2Ir2O7
Physical Review Letters 115 , 056402 (2015)
Classification of stable three-dimensional Dirac semimetals with nontrivial topology
Nature Communications 5 , 4898 (2014)
Quantum criticality of topological phase transitions in 3D interacting electron systems
Nature Physics 10 , 774 (2014)
Emergent topological phenomena in thin films of pyrochlore iridates
Physical Review Letters 112 , 246402 (2014)
Topological protection of bound states against the hybridization
Nature Communications 4 , 1524 (2013)
Theory of topological quantum phase transitions in 3D non-centrosymmetric systems
Physical Review Letters 110 , 086402 (2013)

First-principles Theory

Our team, led by Dr. Choong Hyun Kim, is the first-principles theory team to be established within the IBS Center for Correlated Electron Systems. A key element of our team is the study of emerging phenomena arising from the interplay between correlations and spin-orbit-coupled electronic structure. Utilizing first-principles-based electronic structure calculation methods, we aim to understand and discover novel physical properties of correlated oxides and related systems. Especially, our main interest is in the correlated system with strong spin-orbit coupling effects
Selected Publications
Spin-orbital-entangled Jeff =1/2 state in 3d transition metal oxide CuAl2O4
under review
Topological Superconductivity in Metal/Quantum-Spin-Ice Heterostructures
npj Quantum Materials 2 , 64 (2017)
Interplay of spin-orbit interactions, dimensionality, and octahedral rotations in semimetallic SrIrO3
Physical Review Letters 114 , 016401 (2015)
Orbital chirality and Rashba interaction in magnetic bands
Physical Review B 87 , 041301(R) (2013)
Topological quantum phase transition in transition metal oxide Na2IrO3
Physical Review Letters 108 , 106401 (2012)

Computational Materials Theory

The computational materials theory team led by Dr. Se Young Park aims to understand the emergent phenomena using various simulation tools. Our immediate interest is to understand and predict the electronic, transport, optical properties of the bulk complex oxides and oxide heterostructures. Our computational methods are based on first-principles density functional theory capable of providing realistic material properties and also on numerical many-body methods such as dynamical mean-field theory and random phase approximation to describe the electron correlation of frontier orbitals.
Selected Publications
Charge-order-induced ferroelectricity in LaVO3/SrVO3 superlattices
Physical Review Letters 118 , 087602 (2017)
Flux states and topological phases from spontaneous time-reversal symmetry breaking in CrSi(Ge)Te3-based systems
Physical Review Letters 117 , 257201 (2016)
Charge density distribution and optical response of the LaAlO3/SrTiO3 interface
Physical Review B 87 , 205145 (2013)
Artificial two-dimensional polar metal at room temperature
Nature Communications 9, 1547 (2018)