Drag force on a moving impurity in a spin-orbit-coupled Bose-Einstein condensate

He, Pei-Song; Zhu, Yao-hui; Liu, Wu-Ming

doi:10.1103/physreva.89.053615

Cited by 19 publications

(5 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…( 26) it follows that the critical speed v ℓ,c can depend on the direction v of the motion. This effect has already been addressed in several works [44][45][46][47], which focused on the uniform plane-wave and zero-momentum phases. It has also been found that the drag force can be not parallel to v, and the critical velocity can be different from the sound velocity even in the directions perpendicular to the condensation momentum.…”

Section: Drag Force and Energy Dissipation In The Stripe Phasementioning

confidence: 90%

Drag Force and Superfluidity in the Supersolid Stripe Phase of a Spin-Orbit-Coupled Bose-Einstein Condensate

Martone¹,

SHLYAPNIKOV²

2018

Zh. Eksp. Teor. Fiz.

View full text Add to dashboard Cite

The phase diagram of a spin-orbit-coupled two-component Bose gas includes a supersolid stripe phase, which is featuring density modulations along the direction of the spin-orbit coupling. This phase has been recently found experimentally [J. Li et al., Nature (London) 543, 91 (2017)]. In the present work we characterize the superfluid behavior of the stripe phase by calculating the drag force acting on a moving impurity. Because of the gapless band structure of the excitation spectrum, the Landau critical velocity vanishes if the motion is not strictly parallel to the stripes, and energy dissipation takes place at any speed. Moreover, due to the spin-orbit coupling, the drag force can develop a component perpendicular to the velocity of the impurity. Finally, by estimating the time over which the energy dissipation occurs, we find that for slow impurities the effects of friction are negligible on a time scale up to several seconds, which is comparable with the duration of a typical experiment.

show abstract

Section: Drag Force and Energy Dissipation In The Stripe Phasementioning

confidence: 90%

Drag Force and Superfluidity in the Supersolid Stripe Phase of a Spin-Orbit-Coupled Bose-Einstein Condensate

Martone¹,

SHLYAPNIKOV²

2018

Zh. Eksp. Teor. Fiz.

View full text Add to dashboard Cite

show abstract

“…Finally, the force exerted on the polaritons in the coherent condensate state due to the delta potential imposed by the moving impurity can be expressed as [14,31,35,36]…”

Section: Drag Forcementioning

confidence: 99%

“…This can be obtained by taking t 0 = −∞, which means to turn on the impurity potential adiabatically. Then the impurity-induced excitations over the coherent polariton condensate read [35,37]…”

Section: Drag Forcementioning

confidence: 99%

Drag force of a exciton-polariton condensate under non-resonant pumping

He,

Liang

2020

Preprint

View full text Add to dashboard Cite

Exciton-polariton condensate in semiconductor microcavities constitute a novel kind of nonequilibrium superfluid. In a recent experiment [P. Stepanov, et. al., Nat. Commun. 10, 1038(2019], the dispersion relation of collective excitations in a polariton condensate under the resonant pumping has been investigated with the emphasis on the role of reservoir of long-lived excitons in determining the superfluidity. Inspired by such an experimental advance, we study the superfluidity of a exciton-polaritonn condensate under non-resonant pumping by calculating the drag force exerted on a classical impurity moving in a polariton condensate. For a non-resonant pumped polariton condensate prepared in the gapped phase, due to the reservoir's modes, the drag force can be large when the velocity of the impurity is small. Besides, as the velocity increases, the drag force can decrease. For not very large velocity, the drag force is enhanced if the condensate is tuned to be more dissipative. When the condensate is close to the transition point between the gapped phase and the gapless one, the drag force is similar to that of the equilibrium superfluid. Our present work reveals the effects of the reservoir's modes on the superfluidity properties of a polariton condensate with the non-resonant pumping.

show abstract

“…Whatever level of sophistication should be employed to evaluate the dynamical structure factor, I already foresee a lot of exciting open problems related to the drag force, that could be answered at a basic level within current means. For instance, the anisotropic drag force due to spin-orbit coupling constitutes a new thread of development [420,421].…”

Section: Iv8 Outlook Of This Chaptermentioning

confidence: 99%