2019/10/08 by Chia-Min Chung, Ulrich Schollwöck, Chung, Chia-Min +1 · 1 citation
Computer Science · Mathematics · Physics and Astronomy · #Computational Physics and Python Applications #FOS: Physical sciences #Quantum many-body systems #Strongly Correlated Electrons (cond-mat.str-el) #Tensor decomposition and applications
paper · pdf · doi:10.48550/arxiv.1910.03329
openalex publication_date 2019/10/08 · openalex created_date 2019/10/18 · openalex updated_date 2026/07/28
Finite temperature problems in the strong correlated systems are important but challenging tasks. Minimally entangled typical thermal states (METTS) are a powerful method in the framework of tensor network methods to simulate finite temperature systems, including Fermions and frustrated spins which introduce a sign problem in the typical Monte Carlo methods. In this work, we introduce an extension of the METTS algorithm by using a new basis, the auxiliary matrix product state. This new basis achieves the pre-summation process in the partition function, and thus improve the convergence in the Monte Carlo samplings. The method also has the advantage of simulating the grand canonical ensemble in a computationally efficient way by employing good quantum numbers. We benchmark our method on the spin-1/2 XXZ model on the triangular lattice, and show that the new method outperforms the original METTS as well as the purification methods at sufficiently low temperature, the usual range of applications of METTS. The new method also naturally connects the METTS method to the purification method.