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arXiv · 2011.11971

Field-theoretical aspects of one-dimensional Bose and Fermi gases with contact interactions

Yuta Sekino·Yusuke Nishida
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Abstract

We investigate local quantum field theories for one-dimensional (1D) Bose and Fermi gases with contact interactions, which are closely connected with each other by Girardeau's Bose-Fermi mapping. While the Lagrangian for bosons includes only a two-body interaction, a marginally relevant three-body interaction term is found to be necessary for fermions. Because of this three-body coupling, the three-body contact characterizing a local triad correlation appears in the energy relation for fermions, which is one of the sum rules for a momentum distribution. In addition, we apply in both systems the operator product expansion to derive large-energy and momentum asymptotics of a dynamic structure factor and a single-particle spectral density. These behaviors are universal in the sense that they hold for any 1D scattering length at any temperature. The asymptotics for the Tonks-Girardeau gas, which is a Bose gas with a hardcore repulsion, as well as the Bose-Fermi correspondence in the presence of three-body attractions are also discussed.

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Yuta Sekino, Yusuke Nishida. 2021-04-07. Field-theoretical aspects of one-dimensional Bose and Fermi gases with contact interactions. https://doi.org/10.1103/physreva.103.043307

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