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arXiv · 1806.05405

Two-local qubit Hamiltonians: when are they stoquastic?

Joel Klassen·Barbara M. Terhal
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Abstract

We examine the problem of determining if a 2-local Hamiltonian is stoquastic by local basis changes. We analyze this problem for two-qubit Hamiltonians, presenting some basic tools and giving a concrete example where using unitaries beyond Clifford rotations is required in order to decide stoquasticity. We report on simple results for $n$-qubit Hamiltonians with identical 2-local terms on bipartite graphs. Our most significant result is that we give an efficient algorithm to determine whether an arbitrary $n$-qubit XYZ Heisenberg Hamiltonian is stoquastic by local basis changes.

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Joel Klassen, Barbara M. Terhal. 2019-04-29. Two-local qubit Hamiltonians: when are they stoquastic?. https://doi.org/10.22331/q-2019-05-06-139

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