Ergodicity in a hole-dopped Anderson spin insulator

M. S. Bahovadinov; A. A. Markov; G. V. Shlyapnikov

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arXiv · 2609.36936

Ergodicity in a hole-dopped Anderson spin insulator

M. S. Bahovadinov·A. A. Markov·G. V. Shlyapnikov

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Abstract

An interacting many-body system being localized in the presence of disorder can fail to serve as its own bath. In an electronic system, the charge and spin degrees of freedom can act as thermal baths for each other. In this paper, we study the stability of an Anderson insulator in the spin sector with respect to charge doping. We consider one-dimensional two-component fermions in a lattice with large onsite repulsion ($t-J_{XX}$ model) and with a single hole in a random magnetic field. In the absence of the hole the spin sector is localized in arbitrarily weak random magnetic fields. We argue that a single hole thermalizes the spin chain in the weak disorder limit. In this regime our numerical results indicate ergodicity of the system as a whole and delocalization of the hole. At larger magnetic fields the hole eventually localizes with a finite localization length, and the Anderson spin insulator is restored.

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M. S. Bahovadinov, A. A. Markov, G. V. Shlyapnikov. 2026-09-29. Ergodicity in a hole-dopped Anderson spin insulator. https://arxiv.org/abs/2609.36936

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