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Public Seminar of PhD Candidate:
Half-integer Topological Invariant and its Application in Condensed Matter Systems

Speaker:Mr. Ziang HU
Affiliation:The University of Hong Kong
Date:September 6, 2023 (Wednesday)
Time:2:30 p.m.
Venue:[In Person] Room 522, 5/F, Chong Yuet Ming Physics Building, The University of Hong Kong
Meeting ID: 948 5473 3095
Password: 646470


In this seminar, we elucidate the intricacies of quantum anomalies in condensed matter, with a pronounced emphasis on quantum anomalous semimetals and their associated half-integer topological invariants. By pioneering an extension of topological invariants to half-integer domains, we have unearthed salient properties intrinsic to these semimetals, most notably the emergence of an anomalous boundary current and its concomitant half-quantized Hall conductance. We also purpose experimental methods in probing parity anomaly in quantum anomalous Hall systems by finite-frequency Hall conductance. Furthermore, we shall present our rigorous examination of a discrete time crystal, manifested by extrapolating the 1D Wilson fermion into the temporal dimension. This time crystal enforced by nonsymmorphic symmetry shows irregular dynamical behavior along its mobius twisted instantanous state. This novel construct exhibits distinct dynamical symmetries and maintains remarkable robustness amidst external perturbations. 

Anyone interested is welcome to attend.