Emergent Anomalous Hydrodynamics at Infinite Temperature in a Long-Range XXZ Model

The conventional wisdom suggests that transports of conserved quantities in non-integrable quantum many-body systems at high temperatures are diffusive. However, we discover a counterexample of this paradigm by uncovering anomalous hydrodynamics in a spin-1/2 XXZ chain with power-law couplings. This...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-03
Main Authors: Ang, Yang, Ma, Jinlou, Lei, Ying
Format: Article
Language:English
Subjects:
Anisotropy
Couplings
Eigenvectors
Fluid mechanics
High temperature
Hydrodynamics
Matrix theory
Power law
Transport phenomena
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The conventional wisdom suggests that transports of conserved quantities in non-integrable quantum many-body systems at high temperatures are diffusive. However, we discover a counterexample of this paradigm by uncovering anomalous hydrodynamics in a spin-1/2 XXZ chain with power-law couplings. This model, classified as non-integrable due to its Wigner-Dyson level-spacing statistics in the random matrix theory, exhibits a surprising superdiffusive-ballistic-superdiffusive transport transition by varying the power-law exponent of couplings for a fixed anisotropy. Our findings are verified by multiple observables, including the spin-spin autocorrelator, mean-square displacement, and spin conductivity. Interestingly, we further quantify the degree of quantum chaos using the Kullback-Leibler divergence between the entanglement entropy distributions of the model's eigenstates and a random state. Remarkably, an observed local maximum in the divergence near the transition boundary suggests a link between anomalous hydrodynamics and a suppression of quantum chaos. This work offers another deep understanding of emergent anomalous transport phenomena in a wider range of non-integrable quantum many-body systems
ISSN:2331-8422