Seminar detail: Higher-form symmetry and eigenstate thermalization hypothesis

Date&Time	Tue Nov 14 2023 (17:00 - 18:00)
Speaker	Osamu Fukushima
Affiliation	Kyoto University
Title	Higher-form symmetry and eigenstate thermalization hypothesis
Abstract	The eigenstate thermalization hypothesis (ETH) is a successful framework that provides criteria for thermalization in isolated quantum systems. We elucidate how the presence of higher-form symmetries affects the ETH. Under reasonable assumptions, we analytically show that a p-form symmetry in a (d+1)-dimensional quantum field theory leads to the breakdown of the ETH for many nontrivial (d−p)-dimensional observables. For higher-form (i.e., p≥1) symmetry, this implies the absence of thermalization for observables that are non-local but much smaller than the whole system size. We numerically demonstrate this argument for the (2+1)-dimensional ℤ2 lattice gauge theory. While local observables such as the plaquette operator thermalize even for the mixed symmetry sector, the non-local observable exciting a magnetic dipole instead relaxes to the generalized Gibbs ensemble that takes account of the ℤ2 1-form symmetry.
Remarks
Slide/Video