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arXiv · 2408.14970

A little bit of self-correction

Michael J. Kastoryano·Lasse B. Kristensen·Chi-Fang Chen·András Gilyén
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Abstract

We investigate the emergence of stable subspaces in the low-temperature quantum thermal dynamics of finite spin chains. Our analysis reveals the existence of effective decoherence-free qudit subspaces, persisting for timescales exponential in $\beta$. Surprisingly, the appearance of metastable subspaces is not directly related to the entanglement structure of the ground state(s). Rather, they arise from symmetry relations in low-lying excited states. Despite their stability within a 'phase', practical realization of stable qubits is hindered by susceptibility to symmetry-breaking perturbations. This work highlights that there can be non-trivial quantum behavior in the thermal dynamics of noncommuting many body models, and opens the door to more extensive studies of self-correction in such systems.

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Michael J. Kastoryano, Lasse B. Kristensen, Chi-Fang Chen, András Gilyén. 2024-08-27. A little bit of self-correction. https://doi.org/10.22331/q-2025-08-04-1820

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