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arXiv · 1703.08411

Density-of-states of many-body quantum systems from tensor networks

Fabian Schrodi·Pietro Silvi·Ferdinand Tschirsich·Rosario Fazio·Simone Montangero
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Abstract

We present a technique to compute the microcanonical thermodynamical properties of a manybody quantum system using tensor networks. The Density Of States (DOS), and more general spectral properties, are evaluated by means of a Hubbard-Stratonovich transformation performed on top of a real-time evolution, which is carried out via numerical methods based on tensor networks. As a consequence, the free energy and thermal averages can be also calculated. We test this approach on the one-dimensional Ising and Fermi-Hubbard models. Using matrix product states, we show that the thermodynamical quantities as a function of temperature are in very good agreement with the exact results. This approach can be extended to higher-dimensional system by properly employing other types of tensor networks.

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Fabian Schrodi, Pietro Silvi, Ferdinand Tschirsich, Rosario Fazio, Simone Montangero. 2017-09-06. Density-of-states of many-body quantum systems from tensor networks. https://doi.org/10.1103/physrevb.96.094303

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