2024/08/26 by Shuangyuan Lu, Lu, Shuangyuan
Physics and Astronomy · #Complex Network Analysis Techniques #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Quantum many-body systems #Statistical Mechanics (cond-mat.stat-mech) #Strongly Correlated Electrons (cond-mat.str-el) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.2408.14372
openalex publication_date 2024/08/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Avalanches are believed to be the mechanism behind the transition from many-body localization to the thermal phase. We utilize spin chains with constraints to study the physics of quantum avalanches by exact diagonalization of disordered systems coupled to a thermal bath. Single-spin observables are used to characterize localization and quantify the influence of the thermal bath on disordered spin chains. Constraints on the Hilbert space confine the dynamics to a subspace, effectively reducing the Hilbert space dimension and enabling the study of larger systems with limited computational resources. We study the PXP model, and in addition, we construct spin chains with constraints by searching for constraints with a genetic algorithm to reach larger system sizes. We define quantities to measure the strength of avalanches and use these to compare different models. We find that avalanches are more pronounced in models with constraints compared to those without constraints. Results from exact diagonalization are compared with those from studying the Lindblad master equation. We also identify models that exhibit no thermal phases and find stable ergodicity breaking.