Theorie Kolloquium | January 30, 16:30
Hundness in twisted bilayer graphene and hardness in random quantum circuits
In this talk, we explore two distinct frontiers of many-body physics where sophisticated numerical methods reveal the nature of quantum phases and the boundary of classical hardness. In the first topic, we investigate magic-angle twisted bilayer graphene (MATBG) using dynamical mean-field theory (DMFT) with the numerical renormalization group (NRG) impurity solver. We find that effective Hund interactions, induced by the nonretarded electron-phonon coupling, play a crucial role in causing a robust pseudogap, quantum criticality, and enhancement of pairing susceptibility near filling ±2. In the second topic, we discuss two-dimensional tensor network studies on random quantum circuits on square lattices, where classical complexity changes drastically depending on the gate type.
Seoul National University
0.03
Contact: Fabian Kugler