Strong coupling Bose polarons in a two-dimensional gas

Year: 2020

Authors: Ardila LAP., Astrakharchik GE., Giorgini S.

Autors Affiliation: Leibniz Univ Hannover, Inst Theoret Phys, D-30167 Hannover, Germany; Aarhus Univ, Inst Fys & Astron, DK-8000 Aarhus C, Denmark; Univ Politecn Cataluna, Dept Fis, Campus Nord B4-B5, E-08034 Barcelona, Spain; Univ Trento, Dipartimento Fis, CNR INO BEC Ctr, I-38123 Povo, Trento, Italy.

Abstract: We study the properties of Bose polarons in two dimensions using quantum Monte Carlo techniques. Results for the binding energy, the effective mass, and the quasiparticle residue are reported for a typical strength of interactions in the gas and for a wide range of impurity-gas coupling strengths. A lower and an upper branch of the quasiparticle exist. The lower branch corresponds to an attractive polaron and spans from the regime of weak coupling where the impurity acts as a small density perturbation of the surrounding medium to deep bound states which involve many particles from the bath and extend as far as the healing length. The upper branch corresponds to an excited state where due to repulsion a low-density bubble forms around the impurity but might be unstable against decay into many-body bound states. Interaction effects strongly affect the quasiparticle properties of the polaron. In particular, in the strongly correlated regime, the impurity features a vanishing quasiparticle residue, signaling the transition from an almost free quasiparticle to a bound state involving many atoms from the bath.

Journal/Review: PHYSICAL REVIEW RESEARCH

Volume: 2 (2)      Pages from: 23405-1  to: 23405-8

More Information: This research was funded by the DFG Excellence Cluster QuantumFrontiers. S.G. acknowledges funding from the Provincia Autonoma di Trento. G.E.A. acknowledges funding from the Spanish MINECO (Grant No. FIS2017-84114-C2-1P). The Barcelona Supercomputing Center (The Spanish National Supercomputing Center-Centro Nacional de Supercomputacion) is acknowledged for the provided computational facilities (Grant No. RES-FI-2019-2-0033).
KeyWords: Transport; Physics
DOI: 10.1103/PhysRevResearch.2.023405

Citations: 32
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here