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arXiv · 2408.09636

Exact closed-form unitary transformations of fermionic operators

Francesco A. Evangelista·Ilias Magoulas
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Abstract

Unitary transformations play a fundamental role in many-body physics, and except for special cases, they are not expressible in closed form. We present closed-form expressions for unitary transformations generated by a single fermionic operator for Hermitian and anti-Hermitian generators. We demonstrate the usefulness of these expressions in formal analyses of unitary transformations and numerical applications involving block-diagonalization and Heisenberg dynamics. This work paves the way for new analytical treatments of unitary transformations and numerical many-body methods for fermions.

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Francesco A. Evangelista, Ilias Magoulas. 2024-08-19. Exact closed-form unitary transformations of fermionic operators. https://arxiv.org/abs/2408.09636

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