Dynamical relaxation behaviors of a critical quench
Abstract
We study the universal dynamical relaxation behaviors of a quantum XY chain following a quench, paying special attention to the case in which the initial state is a critical ground state, or the postquenched Hamiltonian is at a critical point of equilibrium quantum phase transition, or both of them are critical. In such a "critical quench," we find very interesting real-time dynamical scaling behaviors and we find crossover phenomena between them. For a quench from a noncritical point to a critical point, we find that, compared to the noncritical quench, the universal power-law scaling behavior does not change; however, there may be a crossover between the exponential decaying behavior and the power-law scaling. For a quench from a critical point to a noncritical point, the power-law scaling behaviors t−3 /2 and t−3 /4 in the noncritical quenches may be changed to t−1 and t−1 /2, respectively. If the prequenched Hamiltonian is set to be a point that is close to but not exactly at a critical point, we find interesting crossover phenomena between different power-law scaling behaviors. We also study the quench from the vicinity of a multicritical point, we find crossover behaviors that are induced by a different mechanism, and we find another crossover exponent. All the results are related to the gap-closing properties of the energy spectrum of the critical points.
- Publication:
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Physical Review B
- Pub Date:
- July 2023
- DOI:
- arXiv:
- arXiv:2305.00160
- Bibcode:
- 2023PhRvB.108a4303Z
- Keywords:
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- Condensed Matter - Statistical Mechanics
- E-Print:
- 9pages, 12 figures, v2