Integrable Free and Interacting Fermions (opens in new tab)

arXiv:2603.11172v1 Announce Type: cross Abstract: Integrability conditions on local Hamiltonians for one-dimensional quantum systems to be free and interacting fermions are introduced. The definition of free fermion is the simultaneous satisfaction of the Yang-Baxter equation and Shastry's decorated star-triangle relation by the $R$-matrix, which is more general than the previous `free-fermion algebra' by Maassarani and more special than free fermions as in the context of exactly solvable qu...