July 10 (Fri) at 13:30 - 14:30, 2020 (JST)
  • Dr. Shoichiro Tsutsui (Special Postdoctoral Researcher, Quantum Hadron Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science (RNC))
  • via Zoom

We investigate an attractively interacting two-component Fermi gas in 1D described by the Gaudin-Yang model with population imbalance. While the Gaudin-Yang model is known as a solvable model based on the thermodynamic Bethe ansatz, the binding energy and mass of poralon at finite temperature and moderate impurity density are still unknown. Moreover, in such a system, quantum Monte Carlo simulation suffers from the sign problem because the population imbalance makes the fermion determinant non-positive definite. In this study, we apply complex Langevin method, a holomorphic extension of the stochastic quantization to overcome the sign problem. We first confirm our numerical results satisfy a criteria for correct convergence [1], and present how the polaron energy depends on temperature and density of impurity. We also compare our results with a recent study based on a diagrammatic approach [2].

*Detailed information about the seminar refer to the email.


  1. K. Nagata, J. Nishimura, S. Shimasaki, Phys. Rev. D 94, 11 (2016).
  2. H. Tajima, S. Tsutsui, T. M. Doi, arXiv:2005.12124