Dissipative free fermions in disguise
Abstract
Recently, a class of spin chains known as ``free fermions in disguise'' (FFD) has been discovered, which possess hidden free-fermion spectra even though they are not solvable via the standard Jordan-Wigner transformation. In this work, we extend this FFD framework to open quantum systems governed by the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) equation. We establish a general class of exactly solvable open quantum systems within the FFD framework: if the Liouvillian frustration graph is claw-free and has a simplicial clique, the Liouvillian possesses a hidden free-fermion spectrum. In particular, the (even-hole, claw)-free condition automatically guarantees this, enabling exact computation of the Liouvillian gap and an infinite-temperature autocorrelation function. Our results provide the first realization of the FFD mechanism in open quantum systems.
Cite
@article{arxiv.2603.22163,
title = {Dissipative free fermions in disguise},
author = {Kohei Fukai and Hironobu Yoshida and Hosho Katsura},
journal= {arXiv preprint arXiv:2603.22163},
year = {2026}
}
Comments
8 pages, 4 figures