Exact Quench Dynamics from Thermal Pure Quantum States
Statistical Mechanics
2026-03-17 v3 Strongly Correlated Electrons
High Energy Physics - Theory
Quantum Physics
Abstract
We present an exact solution of entanglement entropy for the real-time dynamics following a quench from a thermal pure quantum (TPQ) state in an free fermion system. Contrast to the usual linear growth and saturate behavior, the entanglement entropy exhibits a characteristic double-plateau structure. We obtain this behavior exactly using three complementary approaches: two-dimensional (2D) conformal field theory (CFT) on the Klein bottle, an exact numerical evolution based on the matrix Riccati equation, and an asymptotically exact quasiparticle picture.
Cite
@article{arxiv.2510.05346,
title = {Exact Quench Dynamics from Thermal Pure Quantum States},
author = {Hui-Huang Chen},
journal= {arXiv preprint arXiv:2510.05346},
year = {2026}
}
Comments
v3: Revised introduction and conclusion for clarity. Focused on entanglement dynamics. Minor textual improvements. 5+11 pages, 2 figures