Research

Unconventional Superconductivity


One of the most fascinating unconventional superconductors is topological superconductivity with a Fermi surface, so-called Bogoilubov Fermi-surface (BG-FS)After the theoretical proposal of a BG-FS, urgent questions were raised: 1) Stability of BG-FS under the generic interactions  2) Proposals to pin down BG-FS unambiguously. We studied the interaction and disorder effects on BG-FS to answer the question by using the renormalization group method and dimensional analysis. 

Exotic Phase Transition 

Universality is one of the most beautiful concepts in physics, manifested in continuous phase transitions. In strongly correlated systems, however,  there have been various counter-examples lying beyond Landau-Ginzburg theory. We predicted and characterized exotic quantum and thermal transitions using the concept of fractionalization and deconfinement, which can be applied in U(1) spin liquid and high Tc superconductors.  

Competing Physics of Complex Order

The phase diagram of strongly correlated materials represents the existence of a variety of electronic orders. A family of vanadium-based compounds AV3Sb5 (A = K, Rb, Cs) has emerged as one of the interesting platforms to study diverse exotic phases. In our recent work, we show the stability of monolayer AV3Sb5 and discover its fundamentally different symmetry nature compared to the bulk system, which gives rise to significant changes in intertwined physics. 

Related paper:  arXiv:2202.11521