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arXiv · 2504.10774

Ground-State-Based Model Reduction with Unitary Circuits

Shengtao Jiang·Steven R. White
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Abstract

We present a method to numerically obtain low-energy effective models based on a unitary transformation of the ground state. The algorithm finds a unitary circuit that transforms the ground state of the original model to a projected wavefunction with only the low-energy degrees of freedom. The effective model can then be derived using the unitary transformation encoded in the circuit. We test our method on the one-dimensional and two-dimensional square-lattice Hubbard model at half-filling, and obtain more accurate effective spin models than the standard perturbative approach.

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Shengtao Jiang, Steven R. White. 2025-04-15. Ground-State-Based Model Reduction with Unitary Circuits. https://doi.org/10.1103/h1pt-v5kz

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