The diffusive spectral gap of the qubit eSWAP chain

Abstract:We prove that the second-moment Hamiltonian of the open qubit eSWAP chain has a diffusive spectral gap, resolving a conjecture of Li, Zheng, Liu, Jiang, and Liu. We also characterise the ground space on every connected interaction graph with at least five vertices and prove a uniform lower bound for the unnormalised complete-graph gap. We apply these results to sequential and brickwork circuits and prove that the periodic chain also has a diffusive spectral gap.

arXiv:2610.05152 [quant-ph]

(or arXiv:2610.05152v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2610.05152 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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