2025/05/29 by Zhiqiang Huang, Huang, Zhiqiang, Qing-yu Cai +1
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Quantum Physics (quant-ph) #Quantum many-body systems #Spectroscopy and Quantum Chemical Studies #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.2505.23041
openalex publication_date 2025/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This study establishes a universal mechanism for entropy production in isolated quantum systems governed by interactions that induce random-phase fluctuations. By developing a resolvent-based framework, we demonstrate that steady-state entropy generically arises from many-body interactions, independent of specific coupling details, provided the coherent accumulation of systematic biases does not overwhelm the random-phase fluctuations. Analytical arguments reveal that entropy generation is driven by two universal pathways: interaction-induced energy broadening and temporal coarse-graining over exponentially small energy gaps. To quantitatively capture the probability distribution, we introduce a hierarchical ansatz approach. A Lorentzian ansatz models the bulk region, leading to self-consistent equations for the broadening and shift parameters, and yields a logarithmic entropy scaling with interaction strength. For the tail behavior, a Gaussian ansatz is formulated, and the corresponding self-consistent condition is derived and validated. By further combining these profiles into an enhanced Lorentzian-Gaussian hybrid ansatz, we achieve a unified and refined description of the full distribution. Numerical simulations of nonintegrable Ising spin chains confirm the predicted logarithmic entropy scaling and validate the self-consistent equations. Our framework effectively bridges the concepts of observational entropy and von Neumann entropy dynamics, providing predictive tools for thermodynamic behavior in quantum many-body systems. These results resolve longstanding debates about interaction-dependent entropy scaling and offer pathways for entropy control in quantum technologies.