Villazon, TamiroClaeys, Pieter W.Pandey, MohitPolkovnikov, AnatoliChandran, Anushya2024-04-172024-04-172020-09-30T. Villazon, P.W. Claeys, M. Pandey, A. Polkovnikov, A. Chandran. 2020. "Persistent dark states in anisotropic central spin models." Scientific Reports, Volume 10, Issue 1, pp.16080-. https://doi.org/10.1038/s41598-020-73015-12045-2322https://hdl.handle.net/2144/48620Long-lived dark states, in which an experimentally accessible qubit is not in thermal equilibrium with a surrounding spin bath, are pervasive in solid-state systems. We explain the ubiquity of dark states in a large class of inhomogeneous central spin models using the proximity to integrable lines with exact dark eigenstates. At numerically accessible sizes, dark states persist as eigenstates at large deviations from integrability, and the qubit retains memory of its initial polarization at long times. Although the eigenstates of the system are chaotic, exhibiting exponential sensitivity to small perturbations, they do not satisfy the eigenstate thermalization hypothesis. Rather, we predict long relaxation times that increase exponentially with system size. We propose that this intermediate chaotic but non-ergodic regime characterizes mesoscopic quantum dot and diamond defect systems, as we see no numerical tendency towards conventional thermalization with a finite relaxation time.p. 16080Electronicen© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons .org/licenses/by/4.0/.http://creativecommons.org/licenses/by/4.0/Article2024-02-1510.1038/s41598-020-73015-10000-0002-5549-7400 (Polkovnikov, Anatoli)571973