Critical Relaxation in the Quantum Yang–Lee Edge Singularity

We study the relaxation dynamics near the critical points of the Yang–Lee edge singularities (YLESs) in the quantum Ising chain in an imaginary longitudinal field with a polarized initial state. We find that scaling behaviors are manifested in the relaxation process after a non-universal transient t...

Full description

Saved in:
Bibliographic Details
Main Authors: Yue-Mei Sun, Xinyu Wang, Liang-Jun Zhai
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/27/2/170
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We study the relaxation dynamics near the critical points of the Yang–Lee edge singularities (YLESs) in the quantum Ising chain in an imaginary longitudinal field with a polarized initial state. We find that scaling behaviors are manifested in the relaxation process after a non-universal transient time. We show that for the paramagnetic Hamiltonian, the magnetization oscillates periodically with the period being inversely proportional to the gap between the lowest energy level; for the ferromagnetic Hamiltonian, the magnetization decays to a saturated value; while for the critical Hamiltonian, the magnetization increases linearly. A scaling theory is developed to describe these scaling properties. In this theory, we show that for a small- and medium-sized system, the scaling behavior is described by the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><mn>0</mn><mo>+</mo><mn>1</mn><mo>)</mo></mrow></semantics></math></inline-formula>-dimensional YLES.
ISSN:1099-4300