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Seminars»15.12.2022 - Ceren B. Dağ : Dynamical phase transitions and critical slowing down in transverse-field Ising chains

15.12.2022 - Ceren B. Dağ : Dynamical phase transitions and critical slowing down in transverse-field Ising chains

Dynamical phase transitions and critical slowing down in transverse-field Ising chains

Ceren B. Dağ
Harvard University, ITAMP
15 December 2022, Thursday, 14:30
Cavid Erginsoy Seminar Room, Physics Department, 3rd floor

Abstract: Transverse field Ising chain (TFIC) is a paradigmatic model of quantum phase transitions. Unlike long-range interacting TFIC, short-range TFIC under periodic boundary conditions does not host a non-analyticity in the long-time quench dynamics of the magnetization, and hence it does not exhibit a dynamical phase transition. We first show that introducing boundaries, and hence zero edge modes, to the short-range TFIC defines a stationary regime in local magnetizations which leads to a non-analyticity in the long-time quench dynamics. We utilize this non-analyticity to probe quantum critical points and dynamical order profiles in integrable and nonintegrable Ising models. Furthermore, we reveal a prethermal temporal regime upon suddenly quenching to the vicinity of a quantum critical point which is a signature of critical slowing down far from equilibrium. The prethermal regime is analytically found to be self-similar, and its duration is governed by the ground-state energy gap. Based on the analytical insights and numerical evidence, we show that the critically prethermal regime universally exists independently of the location of the probe site, the presence of weak interactions, or the choice of initial state.