Optimal local basis truncation of lattice quantum many-body systems

• URL: http://arxiv.org/abs/2509.17975v1
• Date: Mon, 22 Sep 2025 16:22:54 GMT
• Title: Optimal local basis truncation of lattice quantum many-body systems
• Authors: Peter Majcen, Giovanni Cataldi, Pietro Silvi, Simone Montangero,
• Abstract summary: We show how to optimally reduce the local basis of lattice quantum many-body (QMB) Hamiltonians.<n>The basis truncation exploits the most relevant eigenvalues of the estimated single-site reduced density matrix.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We show how to optimally reduce the local Hilbert basis of lattice quantum many-body (QMB) Hamiltonians. The basis truncation exploits the most relevant eigenvalues of the estimated single-site reduced density matrix (RDM). It is accurate and numerically stable across different model phases, even close to quantum phase transitions. We apply this procedure to different models, such as the Sine-Gordon model, the $\varphi^{4}$ theory, and lattice gauge theories, namely Abelian $\mathrm{U}(1)$ and non-Abelian $\mathrm{SU}(2)$, in one and two spatial dimensions. Our results reduce state-of-the-art estimates of computational resources for classical and quantum simulations.

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