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arXiv · 1911.07439

Finite temperature density matrix embedding theory

Chong Sun·Ushnish Ray·Zhi-Hao Cui·Miles Stoudenmire·Michel Ferrero·Garnet Kin-Lic Chan
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Abstract

We describe a formulation of the density matrix embedding theory at finite temperature. We present a generalization of the ground-state bath orbital construction that embeds a mean-field finite-temperature density matrix up to a given order in the Hamiltonian, or the Hamiltonian up to a given order in the density matrix. We assess the performance of the finite-temperature density matrix embedding on the 1D Hubbard model both at half-filling and away from it, and the 2D Hubbard model at half-filling, comparing to exact data where available, as well as results from finite-temperature density matrix renormalization group, dynamical mean-field theory, and dynamical cluster approximations. The accuracy of finite-temperature density matrix embedding appears comparable to that of the ground-state theory, with at most a modest increase in bath size, and competitive with that of cluster dynamical mean-field theory.

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Chong Sun, Ushnish Ray, Zhi-Hao Cui, Miles Stoudenmire, Michel Ferrero, Garnet Kin-Lic Chan. 2019-11-18. Finite temperature density matrix embedding theory. https://doi.org/10.1103/physrevb.101.075131

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