[Submitted on 9 Jan 2019] (cross-list from cond-mat.quant-gas)
Bose polaron in spherically symmetric trap potentials: Ground states with zero and lower angular momenta
Kano Watanabe · Eiji Nakano · Hiroyuki Yabu
Single-atomic impurities immersed in a dilute Bose gas in the spherically symmetric harmonic trap potentials are studied at zero temperature. In order to find the ground state of the polarons, we present a conditional variational method with fixed expectation values of the total angular momentum operators, and , of the system, using a cranking gauge-transformation for bosons to move them in the frame co-rotating with the impurity. In the formulation, the expectation value is shown to be shared in impurity and bosons, but the value is carried by the impurity due to the rotational symmetry. We also analyze the ground-state properties numerically obtained in this variational method for the system of the attractive impurity-boson interaction, and find that excited boson distributions around the impurity overlap largely with impurity's wave function in their quantum-number spaces and also in the real space because of the attractive interaction employed.
- Comments:
- 31 pages, 6 figures. Some comments, references, and new figures in Fig.3 have been added
- Subjects:
- Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
- arXiv:
- 1901.02847 [pdf]