Dynamical spin-density waves in a spin-orbit-coupled Bose-Einstein condensate

Li, Yan; Qu, Chunlei; Zhang, Yongsheng; Zhang, Chuanwei

doi:10.1103/physreva.92.013635

Cited by 16 publications

(10 citation statements)

References 41 publications

(49 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 we compare the single-band model ( 2) to the full two-component model (1), demonstrating that for the experiment under consideration, all the relevant phenomena result purely from the modified dispersion relationship E − ( p). Even when studying systems with significant population of the upper band such as the dynamical spin-density waves demonstrated in [33], we find that the single-component model ( 2) captures most of the bulk effects: i.e. it correctly models the dynamical behavior of the total density n ↑ + n ↓ , but the significant population of the upper branch breaks the spin-quasimomentum mapping (3).…”

Section: Numerical Simulationsmentioning

confidence: 90%

See 1 more Smart Citation

Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate

et al. 2017

View full text Add to dashboard Cite

A negative effective mass can be realized in quantum systems by engineering the dispersion relation. A powerful method is provided by spin-orbit coupling, which is currently at the center of intense research efforts. Here we measure an expanding spin-orbit coupled Bose-Einstein condensate whose dispersion features a region of negative effective mass. We observe a range of dynamical phenomena, including the breaking of parity and of Galilean covariance, dynamical instabilities, and self-trapping. The experimental findings are reproduced by a single-band Gross-Pitaevskii simulation, demonstrating that the emerging features -shockwaves, soliton trains, self-trapping, etc.-originate from a modified dispersion. Our work also sheds new light on related phenomena in optical lattices, where the underlying periodic structure often complicates their interpretation.

show abstract

Section: Numerical Simulationsmentioning

confidence: 90%

“…One of the theoretical results we wish to convey is that in many cases (e.g., Refs. [32,33]), a single-band model can capture the essential dynamics with modified dispersion:…”

mentioning

confidence: 99%

Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The in-phase oscillations correspond to an ordinary pressure wave, whose propagation speed is determined by the compressibility of the system. Meanwhile, the out-of-phase oscillations are a wave of the density difference between the two components, referred to as spin sound, regarding the two components as two opposite spin states, |↑ and |↓ [18][19][20]. We observe two distinct sound waves propagating with different speeds in the condensate and identify the fast wave with ordinary density sound and the slow wave with spin sound.…”

mentioning

confidence: 82%

Observation of Two Sound Modes in a Binary Superfluid Gas

Kim,

Hong,

Shin

2019

Preprint

View full text Add to dashboard Cite

We study the propagation of sound waves in a binary superfluid gas with two symmetric components. The binary superfluid is constituted using a Bose-Einstein condensate of 23 Na in an equal mixture of two hyperfine ground states. Sound waves are excited in the condensate by applying a local spin-dependent perturbation with a focused laser beam. We identify two distinct sound modes, referred to as density sound and spin sound, where the densities of the two spin components oscillate in phase and out of phase, respectively. The observed sound propagation is explained well by the two-fluid hydrodynamics of the binary superfluid. The ratio of the two sound velocities is precisely measured with no need for absolute density calibration, and we find it in quantitatively good agreement with known interaction properties of the binary system.

show abstract

“…[140][141][142][143][144][145]. The unique and distinguished dynamical feature of these systems is the coupling between the spin dynamics and motional degrees of freedom (such as center-of-mass motion).…”

Section: Collective Dynamics: Zitterbewegungmentioning

confidence: 99%

Properties of spin–orbit-coupled Bose–Einstein condensates

et al. 2016

Self Cite

View full text Add to dashboard Cite

The experimental and theoretical research of spin-orbit-coupled ultracold atomic gases has advanced and expanded rapidly in recent years. Here, we review some of the progress that either was pioneered by our own work, has helped to lay the foundation, or has developed new and relevant techniques. After examining the experimental accessibility of all relevant spin-orbit coupling parameters, we discuss the fundamental properties and general applications of spin-orbit-coupled Bose-Einstein condensates (BECs) over a wide range of physical situations. For the harmonically trapped case, we show that the ground state phase transition is a Dicke-type process and that spin-orbit-coupled BECs provide a unique platform to simulate and study the Dicke model and Dicke phase transitions. For a homogeneous BEC, we discuss the collective excitations, which have been observed experimentally using Bragg spectroscopy. They feature a roton-like minimum, the softening of which provides a potential mechanism to understand the ground state phase transition. On the other hand, if the collective dynamics are excited by a sudden quenching of the spin-orbit coupling parameters, we show that the resulting collective dynamics can be related to the famous Zitterbewegung in the relativistic realm. Finally, we discuss the case of a BEC loaded into a periodic optical potential. Here, the spin-orbit coupling generates isolated flat bands within the lowest Bloch bands whereas the nonlinearity of the system leads to dynamical instabilities of these Bloch waves. The experimental verification of this instability illustrates the lack of Galilean invariance in the system.

show abstract

Dynamical spin-density waves in a spin-orbit-coupled Bose-Einstein condensate

Cited by 16 publications

References 41 publications

Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate

Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate

Observation of Two Sound Modes in a Binary Superfluid Gas

Properties of spin–orbit-coupled Bose–Einstein condensates

Contact Info

Product

Resources

About