Quantum Spin Dynamics of Individual Neutral Impurities Coupled to a Bose-Einstein Condensate

Schmidt, Felix; Mayer, Daniel; Bouton, Quentin; Adam, Daniel; Lausch, Tobias; Spethmann, Nicolas; Widera, Artur

doi:10.1103/physrevlett.121.130403

Cited by 53 publications

(57 citation statements)

References 51 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…b) Impurity–bath interaction in the collision channel

true| m_{normali}, m_{normalb} true〉 \equiv true| F_{normali} = 3, m_{normali} true〉 \otimes true| F_{normalb} = 1, m_{normalb} true〉

Section: The Impurity–bath Systemmentioning

confidence: 99%

“…SE successively pumps Cs impurities into

m_{normali} = - 3

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

“…By contrast, when the system is prepared in the global ground state

| m_{i} = 3, m_{b} = 1 〉

, no SE occurs. Importantly, SE occurs in addition to elastic collisions and a detailed study of respective scattering cross sections by closed‐channel scattering calculations has revealed a ratio between elastic and SE cross sections of roughly 10. Therefore, once immersed, Cs impurities remain thermalized in the ultracold Rb bath due to the dominance of elastic collisions.…”

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

“…Second, angular momentum exchange (also spin exchange, SE) is utilized to temporally and spatially track the spatial overlap of impurities and the Rb bath, where individual collision events are encoded in the impurity spin state rather than its momentum. Thereby, the successful immersion of impurities in a quantum bath and low‐energy interaction features, that is, SE in quanta of

2 ℏ

in a single collision and a series of previously unreported narrow Feshbach resonances in multiple collision channels have been identified. A common feature of those studies is the use of individual impurities as tracers for single‐particle interaction.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Motional and Spin Dynamics of Individual Neutral Impurities in an Ultracold Gas

Schmidt¹,

Mayer²,

Lausch³

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

Recent studies on the dynamics of single, neutral impurities immersed in an ultracold gas are reviewed. This paradigmatic model system is realized by the controlled doping of single Caesium atoms into an ultracold Rubidium gas. Interaction between the impurity and the gas in both the motional and internal degrees of freedom is studied for a broad range of bath temperatures in the thermal and quantum‐degenerate regime. Tracing single‐atom diffusion it is found that, even for a granular bath, where the assumption of a continuous medium is not fulfilled, a modified Langevin equation yields excellent predictions for tracer diffusion. Numerical modeling of impurity dynamics in a three‐dimensional superfluid bath shows the emergence of a prethermalized state for intermediate times due to the existence of a superfluid critical momentum, while for lower dimensions the effect of thermal phonons dominates and obstructs the formation of such nonthermal states. Finally, unleashing the quasi‐spin degree of freedom, the authors observe and control spin‐exchange dynamics between individual impurities and the bath. Moreover, a regime of sympathetic impurity cooling is realized, where the internal‐state coherence of the impurity is preserved. In the future, control over the motional and spin‐degree of freedom will enable using individual impurities as thermalized, localized, minimally invasive quantum probes for a quantum fluid.

show abstract

“…b) Impurity–bath interaction in the collision channel

true| m_{normali}, m_{normalb} true〉 \equiv true| F_{normali} = 3, m_{normali} true〉 \otimes true| F_{normalb} = 1, m_{normalb} true〉

Section: The Impurity–bath Systemmentioning

confidence: 99%

“…SE successively pumps Cs impurities into

m_{normali} = - 3

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

“…By contrast, when the system is prepared in the global ground state

| m_{i} = 3, m_{b} = 1 〉

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

Section: Spin Dynamic Of Impurities In a Gasmentioning

confidence: 99%

2 ℏ

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Motional and Spin Dynamics of Individual Neutral Impurities in an Ultracold Gas

Schmidt¹,

Mayer²,

Lausch³

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

show abstract

Competing few-body correlations in ultracold Fermi polarons

Liu,

Cui

2024

AAPPS Bull.

View full text Add to dashboard Cite

Polaron, a typical quasi-particle that describes a single impurity dressed with surrounding environment, serves as an ideal platform for bridging few- and many-body physics. In particular, different few-body correlations can compete with each other and lead to many intriguing phenomena. In this work, we review the recent progresses made in understanding few-body correlation effects in attractive Fermi polarons of ultracold gases. By adopting a unified variational ansatz that incorporates different few-body correlations in a single framework, we will discuss their competing effects in Fermi polarons when the impurity and majority fermions have the same or different masses. For the equal-mass case, we review the nature of polaron-molecule transition that is driven by two-body correlations, and especially highlight the finite momentum character and huge degeneracy of molecule states. For the mass-imbalanced case, we focus on the smooth crossover between polaron and various dressed clusters that originate from high-order correlations. These competing few-body correlations reviewed in Fermi polarons suggest a variety of exotic new phases in the corresponding many-body system of Fermi-Fermi mixtures.

show abstract