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arXiv · 2404.05686

Chebyshev pseudosite matrix product state approach for cluster perturbation theory

Pei-Yuan Zhao·Ke Ding·Shuo Yang
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Abstract

We introduce the Chebyshev pseudosite matrix product state approach (ChePSMPS) as a solver for cluster perturbation theory (CPT), crucial for simulating spectral functions in two-dimensional electron-phonon ($e$-ph) coupling systems. ChePSMPS distinguishes itself from conventional exact diagonalization solvers by supporting larger clusters, thereby significantly mitigating finite-size effects. Free from the fermion sign problem, ChePSMPS enhances its ability to explore $e$-ph effects and generate high-resolution spectral functions in doped Mott insulators. We use this method to simulate the spectra for both one- and two-dimensional Hubbard-Holstein models, highlighting its superiority over other methods. Our findings validate ChePSMPS as a powerful and reliable Green's function solver. In conjunction with embedding methods, ChePSMPS emerges as an essential tool for simulating strongly correlated $e$-ph coupling systems.

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Pei-Yuan Zhao, Ke Ding, Shuo Yang. 2024-04-08. Chebyshev pseudosite matrix product state approach for cluster perturbation theory. https://arxiv.org/abs/2404.05686

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