• DOI:10.1103/PhysRevB.89.085119
• Corpus ID: 46955038

Diagrammatic Monte Carlo study of the Fermi polaron in two dimensions

@article{Vlietinck2014DiagrammaticMC,
  title={Diagrammatic Monte Carlo study of the Fermi polaron in two dimensions},
  author={J. Vlietinck and Jan Ryckebusch and Kris Van Houcke},
  journal={Physical Review B},
  year={2014},
  volume={89},
  pages={085119}
}

• J. Vlietinck, J. Ryckebusch, K. V. Houcke
• Published 17 February 2014
• Physics
• Physical Review B

Westudythepropertiesofthetwo-dimensionalFermipolaronmodelinwhichanimpurityattractivelyinteracts with a Fermi sea of particles in the zero-range limit. We use a diagrammatic Monte Carlo (DiagMC) method which allows us to sample a Feynman diagrammatic series to very high order. The convergence properties of the series and the role of multiple particle-hole excitations are discussed. We study the polaron and molecule energy as a function of the coupling strength, revealing a transition from a polaron to a molecule in the ground state. We find a value for the critical interaction strength which complies with the experimentally measured one and predictions from variational methods. For all considered interaction strengths, the polaron Z factor from the full diagrammatic series almost coincides with the one-particle-hole result. We also formally link the DiagMC and the variational approaches for the polaron problem at hand.