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arXiv · 2601.01641

Ab initio quantum embedding at finite temperature with density matrix embedding theory

Laurence Giordano·Y. Stanley Tan·Zhi-Hao Cui·Chong Sun
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Abstract

We present a finite-temperature extension of density matrix embedding theory (FT-DMET) for realistic crystalline systems. We describe a practical framework for constructing extended bath orbitals, solving the embedding problem, and performing DMET self-consistency at finite temperature. To reduce computational cost, we introduce strategies based on mutual-information-guided bath truncation, controlled treatment of the thermal electron number without explicit optimization, and the use of low-temperature impurity solvers and one-shot FT-DMET in the low-temperature regime. We apply this approach to periodic hydrogen chains and square lattices to characterize their finite-temperature phases. We observe the Pomeranchuk-like effect in one dimension and enhanced stability of long-range order in two dimensions.

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Laurence Giordano, Y. Stanley Tan, Zhi-Hao Cui, Chong Sun. 2026-01-04. Ab initio quantum embedding at finite temperature with density matrix embedding theory. https://arxiv.org/abs/2601.01641

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