Medium-induced interaction between impurities in a Bose-Einstein condensate

Abstract:

We consider two heavy particles immersed in a Bose-Einstein condensate in three dimensions and compute their mutual interaction induced by excitations of the medium. For an ideal Bose gas, the induced interaction is Newtonian up to a shift in distance, which depends on the coupling strength between impurities and Bosons. For a real BEC, we find that, on short distances, the induced potential is dominated by three-body physics of a single Boson bound to the impurities, leading to an Efimov potential. At large distances of the order of the healing length, a Yukawa potential emerges instead. In particular, we find that both regimes are realized for all impurity-boson couplings and determine the corresponding crossover scales. The transition from the real to the ideal condensate at low gas parameters is investigated.

M. Drescher, M. Salmhofer, T. Enss, “Medium-induced interaction between impurities in a Bose-Einstein condensate”, Phys. Rev. A 107, 063301 (2023).

https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.063301

Related to Project C03, C02