Fig. 5: Effect of a defect on the energy crossing.
From: Emergence of a Bose polaron in a small ring threaded by the Aharonov-Bohm flux
a The energy for P = 0 and P = −2π as a function of the flux with and without a defect. Solid lines are for the unperturbed system; dashed lines correspond to aN = 0.01. Other parameters of the system are N = 19, γ = 0.2, and c/g = 1. b Eq. (13) in the thermodynamic limit as a function of c/g for different boson-boson interactions γ. The data were obtained with the mean-field ansatz.
