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Probing transport in quantum many-fermion simulations via quantum loop topography

Cornell Affiliated Author(s)

Author

Y. Zhang
C. Bauer
P. Broecker
S. Trebst
Eun-Ah Kim

Abstract

Quantum many-fermion systems give rise to diverse states of matter that often reveal themselves in distinctive transport properties. While some of these states can be captured by microscopic models accessible to numerical exact quantum Monte Carlo simulations, it nevertheless remains challenging to numerically access their transport properties. Here, we demonstrate that quantum loop topography (QLT) can be used to directly probe transport by machine learning current-current correlations in imaginary time. We showcase this approach by studying the emergence of superconducting fluctuations in the negative-U Hubbard model and a spin-fermion model for a metallic quantum critical point. For both sign-free models, we find that the QLT approach detects a change in transport in very good agreement with their established phase diagrams. These proof-of-principle calculations combined with the numerical efficiency of the QLT approach point a way to identify hitherto elusive transport phenomena such as non-Fermi liquids using machine learning algorithms. © 2019 American Physical Society.

Date Published

Journal

Physical Review B

Volume

99

Issue

16

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065502690&doi=10.1103%2fPhysRevB.99.161120&partnerID=40&md5=816c920881adafc3a857e21a6f038dd3

DOI

10.1103/PhysRevB.99.161120

Group (Lab)

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