Strong coupling Bose polarons in a two-dimensional gas

verfasst von: L. A. Peña Ardila, G. E. Astrakharchik, S. Giorgini
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.
Organisationseinheit(en): QuantumFrontiers
Institut für Theoretische Physik
Externe Organisation(en): Universitat Politècnica de Catalunya
Università degli Studi di Trento
Typ: Artikel
Journal: Physical Review Research
Band: 2
Publikationsdatum: 26.06.2020
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Physik und Astronomie (insg.)
Elektronische Version(en): https://doi.org/10.1103/PhysRevResearch.2.023405 (Zugang: Offen)

BibTeX

@article{5fba53aeb3bb401bb911b7e66006aef0,
title = "Strong coupling Bose polarons in a two-dimensional gas",
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.",
author = "Ardila, {L. A. Pe{\~n}a} and Astrakharchik, {G. E.} and S. Giorgini",
year = "2020",
month = jun,
day = "26",
doi = "10.1103/PhysRevResearch.2.023405",
language = "English",
volume = "2",
journal = "Physical Review Research",
publisher = "American Physical Society",
number = "2",
}