Quantum beat spectroscopy of repulsive Bose polarons

A. M. Morgen; S. S. Balling; K. Knakkergaard Nielsen; T. Pohl; G. M. Bruun; J. J. Arlt

doi:10.48550/arXiv.2310.18183

Quantum beat spectroscopy of repulsive Bose polarons

A. M. Morgen, S. S. Balling, K. Knakkergaard Nielsen, T. Pohl, G. M. Bruun, J. J. Arlt

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

1 Citation (Scopus)

Abstract

The physics of impurities in a bosonic quantum environment is a paradigmatic and challenging many-body problem. Here, this problem is investigated for impurities with strong repulsive interactions based on Ramsey interferometry in a quantum degenerate gas of K39 atoms. We observe revivals in the amplitude of the interferometric signal and identify them as beat signals between two coexisting quasiparticle branches, the attractive and repulsive polarons. The interferometric signal allows for an extraction of their energies for a wide range of interaction strengths, thus resolving outstanding discrepancies in earlier spectroscopic measurements. Furthermore, we identify several dynamical regimes in the formation of the repulsive Bose polaron. Our results improve the understanding of quantum impurities interacting strongly with a bosonic environment and show how short-lived nonequilibrium many-body states can be probed using quantum beat spectroscopy.

Original language	English
Article number	L022002
Journal	Physical Review Research
Volume	7
Issue	2
ISSN	2643-1564
DOIs	https://doi.org/10.48550/arXiv.2310.18183 https://doi.org/10.1103/PhysRevResearch.7.L022002
Publication status	Published - Apr 2025

Access to Document

Library access?

Check availability with the Royal Danish Library

Cite this

@article{a4c2f7fc8a614b80bd0afda21d9a9f8c,

title = "Quantum beat spectroscopy of repulsive Bose polarons",

abstract = "The physics of impurities in a bosonic quantum environment is a paradigmatic and challenging many-body problem. Here, this problem is investigated for impurities with strong repulsive interactions based on Ramsey interferometry in a quantum degenerate gas of K39 atoms. We observe revivals in the amplitude of the interferometric signal and identify them as beat signals between two coexisting quasiparticle branches, the attractive and repulsive polarons. The interferometric signal allows for an extraction of their energies for a wide range of interaction strengths, thus resolving outstanding discrepancies in earlier spectroscopic measurements. Furthermore, we identify several dynamical regimes in the formation of the repulsive Bose polaron. Our results improve the understanding of quantum impurities interacting strongly with a bosonic environment and show how short-lived nonequilibrium many-body states can be probed using quantum beat spectroscopy.",

author = "Morgen, {A. M.} and Balling, {S. S.} and Nielsen, {K. Knakkergaard} and T. Pohl and Bruun, {G. M.} and Arlt, {J. J.}",

note = "Publisher Copyright: {\textcopyright} 2025 authors. Published by the American Physical Society.",

year = "2025",

month = apr,

doi = "10.48550/arXiv.2310.18183",

language = "English",

volume = "7",

journal = " Physical Review Research ",

issn = "2643-1564",

publisher = "American Physical Society",

number = "2",

}

TY - JOUR

T1 - Quantum beat spectroscopy of repulsive Bose polarons

AU - Morgen, A. M.

AU - Balling, S. S.

AU - Nielsen, K. Knakkergaard

AU - Pohl, T.

AU - Bruun, G. M.

AU - Arlt, J. J.

PY - 2025/4

Y1 - 2025/4

N2 - The physics of impurities in a bosonic quantum environment is a paradigmatic and challenging many-body problem. Here, this problem is investigated for impurities with strong repulsive interactions based on Ramsey interferometry in a quantum degenerate gas of K39 atoms. We observe revivals in the amplitude of the interferometric signal and identify them as beat signals between two coexisting quasiparticle branches, the attractive and repulsive polarons. The interferometric signal allows for an extraction of their energies for a wide range of interaction strengths, thus resolving outstanding discrepancies in earlier spectroscopic measurements. Furthermore, we identify several dynamical regimes in the formation of the repulsive Bose polaron. Our results improve the understanding of quantum impurities interacting strongly with a bosonic environment and show how short-lived nonequilibrium many-body states can be probed using quantum beat spectroscopy.

AB - The physics of impurities in a bosonic quantum environment is a paradigmatic and challenging many-body problem. Here, this problem is investigated for impurities with strong repulsive interactions based on Ramsey interferometry in a quantum degenerate gas of K39 atoms. We observe revivals in the amplitude of the interferometric signal and identify them as beat signals between two coexisting quasiparticle branches, the attractive and repulsive polarons. The interferometric signal allows for an extraction of their energies for a wide range of interaction strengths, thus resolving outstanding discrepancies in earlier spectroscopic measurements. Furthermore, we identify several dynamical regimes in the formation of the repulsive Bose polaron. Our results improve the understanding of quantum impurities interacting strongly with a bosonic environment and show how short-lived nonequilibrium many-body states can be probed using quantum beat spectroscopy.

UR - http://www.scopus.com/inward/record.url?scp=105001858306&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2310.18183

DO - 10.48550/arXiv.2310.18183

M3 - Journal article

AN - SCOPUS:105001858306

SN - 2643-1564

VL - 7

JO - Physical Review Research

JF - Physical Review Research

IS - 2

M1 - L022002

ER -

Quantum beat spectroscopy of repulsive Bose polarons

Abstract

Access to Document

Library access?

Other files and links

Fingerprint

Cite this