The Geometry of Lee-Yang Tensors

Abstract:We provide a geometric description of Lee-Yang tensors, building upon several recent results of Bravyi, Gosset, Liu, and Wong. By applying tools from complex Perron-Frobenius theory, we generalize one of their key lemmas to bound the spectral ratio of non-normal operators with Lee-Yang radius greater than one. As a direct consequence, we provide a local-to-global principle for bounding spectral gaps of Suzuki-Fisher Hamiltonians, a family of $2$-local Hamiltonians, using only the Lee-Yang radius of each local operator to bound the gap from below. On the other hand, we develop a simple perturbative technique to show that the Gibbs states of $k$-local Hamiltonians, $k \geq 3$, cannot have Lee-Yang radius at least one for all inverse temperatures $\beta \geq 0$. We apply this same method to conclude that Suzuki-Fisher Hamiltonians are precisely those Hamiltonians whose Gibbs states are Lee-Yang at all inverse temperatures $\beta \geq 0$.

Quantum Physics (quant-ph); Mathematical Physics (math-ph); Complex Variables (math.CV)

arXiv:2610.09485 [quant-ph]

(or arXiv:2610.09485v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2610.09485 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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