A complex Langevin approach to ultracold fermions

Abstract

The theoretical treatment of Fermi systems consisting of particles with unequal masses is challenging. Even in one spatial dimension analytic solutions are limited to special configurations and numerical progress with Monte Carlo simulations is hindered by the sign-problem. To circumvent this issue, we exploit the Complex Langevin approach and study one-dimensional mass-imbalanced two-component Fermi gases with attractive and repulsive interactions. We find perfect agreement with results obtained by other methods in a range of parameter space. Promisingly, our approach is not limited to the specific model presented here and can easily be extended to finite spin polarization and, most notably, can also be applied in higher dimensions.

7 pages, 2 figures. Proceedings of RPMBT19, Pohang, South Korea

References in corpus (5)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
• Computational complexity and fundamental limitations to fermionic quantum Monte Carlo simulations
• Can stochastic quantization evade the sign problem? -- the relativistic Bose gas at finite chemical potential
• Evolution from few- to many-body physics in one-dimensional Fermi systems: One- and two-body density matrices, and particle-partition entanglement

Cited by in corpus (7)

• One-dimensional mixtures of several ultracold atoms: a review
• Complex Langevin and other approaches to the sign problem in quantum many-body physics
• Langevin Simulations of a Long Range Electron Phonon Model
• Finite-temperature equation of state of polarized fermions at unitarity
• In-medium bound states of two bosonic impurities in a one-dimensional Fermi gas
• Spin Polarized Non-Relativistic Fermions in 1+1 Dimensions
• Pairing patterns in one-dimensional spin- and mass-imbalanced Fermi gases