CMSA Topological Quantum Matter: Extracting the quantum Hall conductance from a single bulk wavefunction from the modular flow


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September 28, 2022 9:00 am - 10:00 am
CMSA, 20 Garden St, G10
Address: 1 Oxford Street, Cambridge, MA 02138 USA

Ruihua Fan - Harvard University

One question in the study of topological phases is to identify the topological data from the ground state wavefunction without accessing the Hamiltonian. Since local measurement is not enough, entanglement becomes an indispensable tool. Here, we use modular Hamiltonian (entanglement Hamiltonian) and modular flow to rephrase previous studies on topological entanglement entropy and motivate a natural generalization, which we call the entanglement linear response. We will show how it embraces a previous work by Kim&Shi et al on the chiral central charge, and furthermore, inspires a new formula for the quantum Hall conductance.