题目：Theory of Superconducting v=2/3 Fractional Quantum Hall Edge States

报告人：廉骉 助理教授，普林斯顿大学

时间：2025年7月18日（周五）上午10:00

地点：腾讯会议（会议号：370-816-760）

报告摘要：

Quantum Hall edge states in proximity to a superconductor (SC) usually acquire a non-quantized electron-to-hole conversion probability in transport, due to non-universal SC couplings and disorders. We show that the situation can be the opposite in the v=2/3 fractional quantum Hall (FQH) edge states with SC proximity, where disordered SC-couplings can drive the edge states into an infinite set of stable phases with quantized electron-to-hole conversion probability along a long edge. Each phase is dominated by a disordered SC-coupling that tunnels q_N Cooper pairs. We predict that this gives rise to a quantized downstream resistance in an FQH-SC junction, serving as a quantized electrical transport signature beyond the Hall conductance. Higher-order nonlinear transport due to irrelevant Cooper pair tunnelings or vortex dissipations is further studied, which becomes dominant when the edge is in a normal phase. Our results reveal a rich landscape of disorder-stabilized phases in FQH edge states with SC proximity, which may as well apply to the recently experimentally realized fractional Chern insulator.

报告人简介：

Biao Lian is an assistant professor at the Department of Physics, Princeton University since 2020. He received his B.Sc. from the Department of Physics, Tsinghua University in 2012, and completed Ph.D. from Stanford University in 2017. He then worked as a postdoctoral fellow in Princeton Center for Theoretical Science from 2017 to 2020. He received awards including Sloan Research Fellowship (2021) and NSF early career award (2022). His research interests are theoretical studies of topological condensed matter physics, low-dimensional quantum systems, and nonequilibrium many-body quantum dynamics.