Impurity in a Bose-Einstein condensate: Study of the attractive and repulsive branch using quantum Monte Carlo methods
Anno: 2015
Autori: Ardila LAP., Giorgini S.
Affiliazione autori: Univ Trento, Dipartimento Fis, I-38123 Povo, Trento, Italy; CNR INO BEC Ctr, I-38123 Povo, Trento, Italy
Abstract: We investigate the properties of an impurity immersed in a dilute Bose gas at zero temperature using quantum Monte Carlo methods. The interactions between bosons are modeled by a hard-sphere potential with scattering length a, whereas the interactions between the impurity and the bosons are modeled by a short-range, square-well potential where both the sign and the strength of the scattering length b can be varied by adjusting the well depth. We characterize the attractive and the repulsive polaron branch by calculating the binding energy and the effective mass of the impurity. Furthermore, we investigate the structural properties of the bath, such as the impurity-boson contact parameter and the change of the density profile around the impurity. At the unitary limit of the impurity-boson interaction, we find that the effective mass of the impurity remains smaller than twice its bare mass, while the binding energy scales with (h) over bar (2)n(2/3) / m, where n is the density of the bath and m is the common mass of the impurity and the bosons in the bath. The implications for the phase diagram of binary Bose-Bose mixtures at low concentrations are also discussed.
Giornale/Rivista: PHYSICAL REVIEW A
Volume: 92 (3) Da Pagina: 033612-1 A: 033612-12
Parole chiavi: GROUND-STATE ENERGY; POLARON; MIXTURE; MODELDOI: 10.1103/PhysRevA.92.033612Citazioni: 141dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-04-14Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui