# Negative-Mass Hydrodynamics in a Spin-Orbit-Coupled Bose-Einstein Condensate.

@article{Khamehchi2017NegativeMassHI, title={Negative-Mass Hydrodynamics in a Spin-Orbit-Coupled Bose-Einstein Condensate.}, author={M. A. Khamehchi and Khalid Hossain and M. E. Mossman and Yongping Zhang and Thomas Busch and Michael McNeil Forbes and P. Engels}, journal={Physical review letters}, year={2017}, volume={118 15}, pages={ 155301 } }

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… Expand

#### Paper Mentions

#### 65 Citations

Negative-Mass Effects in Spin-Orbit Coupled Bose-Einstein Condensates.

- Physics, Medicine
- Physical review letters
- 2018

It is shown that spin-orbit coupled Bose-Einstein condensates may access regimes where both mass parameters controlling the propagation and diffusion of the condensate are negative, which leads to the novel phenomenon of counterpropagating self-interfering packets. Expand

Spin-orbit-coupling induced localization in the expansion of an interacting Bose-Einstein condensate

- Physics
- 2017

By developing a hydrodynamic formalism, we investigate the expansion dynamics of the single-minimum phase of a binary spin-orbit coupled Bose-Einstein condensate, after releasing from an external… Expand

Spin dynamics of a spin-orbit-coupled Bose-Einstein condensate in a shaken harmonic trap

- Physics
- 2019

We propose a mechanism to realize nontrivial spin dynamics in a one-dimensional spin-orbit-coupled BoseEinstein condensate by abruptly shaking the harmonic trap. Continuously varying the shaking… Expand

Negative-Mass Instability of the Spin and Motion of an Atomic Gas Driven by Optical Cavity Backaction.

- Physics, Medicine
- Physical review letters
- 2018

A spin-orbit interaction between the collective spin precession and center-of-mass motion of a trapped ultracold atomic gas is realized, mediated by spin- and position-dependent dispersive coupling to a driven optical cavity, driving exponential growth of a correlated mode of the hybrid system. Expand

Coherent spin mixing via spin-orbit coupling in Bose gases

- Physics
- 2019

We study beyond-mean-field properties of interacting spin-1 Bose gases with synthetic Rashba-Dresselhaus spin-orbit coupling at low energies. We derive a many-body Hamiltonian following a… Expand

Modulation instability associated nonlinear dynamics of spin-orbit coupled Bose-Einstein condensates

- Physics
- 2018

We study pattern-forming nonlinear dynamics starting from a continuous wave state of quasi-one-dimensional two-component Bose-Einstein condensates with synthetic spin-orbit coupling induced by Raman… Expand

Collective dipole oscillations of a spin-orbit coupled Fermi gas

- Physics, Medicine
- Scientific Reports
- 2018

This work split the degeneracy of three hyperfine states in the ground manifold, and independently couple consecutive spin states with the equal Raman transitions to pave the way towards the characterization of spin-orbit-coupled fermions with large spin in the strong coupling regime. Expand

Bloch oscillations of spin-orbit-coupled cold atoms in an optical lattice and spin-current generation

- Physics
- 2019

We study the Bloch oscillation dynamics of a spin-orbit-coupled cold atomic gas trapped inside a one-dimensioanl optical lattice. The eigenspectra of the system is identified as two interpenetrating… Expand

Collisionally Inhomogeneous Bose-Einstein Condensates with a Linear Interaction Gradient.

- Physics, Medicine
- Physical review letters
- 2020

The evolution of a collisionally inhomogeneous matter wave in a spatial gradient of the interaction strength is studied, providing new understanding of collapse processes for solitons, and opens interesting connections to other nonlinear instabilities. Expand

Spin-orbit-coupled bosons interacting in a two-dimensional harmonic trap

- Physics
- 2020

A system of bosons in a two-dimensional harmonic trap in the presence of Rashba-type spin-orbit coupling is investigated. An analytic treatment of the ground state of a single atom in the… Expand

#### References

SHOWING 1-10 OF 55 REFERENCES

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

- Physics
- 2015

Synthetic spin-orbit (SO) coupling, an important ingredient for quantum simulation of many exotic condensed matter physics, has recently attracted considerable attention. The static and dynamic… Expand

Collective dipole oscillations of a spin-orbit coupled Bose-Einstein condensate.

- Physics, Medicine
- Physical review letters
- 2012

An experimental study of the collective dipole oscillation of a spin-orbit coupled Bose-Einstein condensate in a harmonic trap and experimentally demonstrates a unique feature of the spin- orbit coupled system predicted by a sum-rule approach, stating that spin polarization susceptibility can be measured via the dynamics of dipoles oscillation. Expand

Observation of Zitterbewegung in a spin-orbit-coupled Bose-Einstein condensate

- Physics
- 2013

Spin-orbit coupled ultra-cold atoms provide an intriguing new avenue for the study of rich spin dynamics in superfluids. In this Letter, we observe Zitterbewegung, the simultaneous velocity (thus… Expand

Spin-orbit-coupled Bose-Einstein condensates in a one-dimensional optical lattice.

- Physics, Medicine
- Physical review letters
- 2015

The lack of Galilean invariance in the spin-orbit-coupled Bose-Einstein condensate loaded into a translating optical lattice is experimentally demonstrated, which leads to anisotropic behavior of the condensates depending on the direction of translation of the lattice. Expand

Observation of dynamical instability for a Bose-Einstein condensate in a moving 1D optical lattice.

- Physics, Medicine
- Physical review letters
- 2004

Deeply in the unstable region of the unstable dynamics of a harmonically trapped Bose-Einstein condensate loaded into a 1D moving optical lattice, the rapid appearance of complex structures in the atomic density profile is observed, as a consequence of the condensing phase uniformity breakdown. Expand

Superfluid Density of a Spin-Orbit-Coupled Bose Gas

- Physics
- 2016

We discuss the superfluid properties of a Bose-Einstein condensed gas with spin-orbit coupling, recently realized in experiments. We find a finite normal fluid density $\rho_n$ at zero temperature… Expand

Spin–orbit-coupled Bose–Einstein condensates

- Physics, Medicine
- Nature
- 2011

The engineered SO coupling in a neutral atomic Bose–Einstein condensate sets the stage for the realization of topological insulators in fermionic neutral atom systems and develops a many-body theory that provides quantitative agreement with the observed location of the transition. Expand

Realization of two-dimensional spin-orbit coupling for Bose-Einstein condensates

- Physics, Medicine
- Science
- 2016

The realization of 2D SO coupling with advantages of small heating and topological stability opens a broad avenue in cold atoms to study exotic quantum phases, including topological superfluids. Expand

Self-trapping of Bose-Einstein condensates in optical lattices

- Physics
- 2006

The self-trapping phenomenon of Bose-Einstein condensates (BECs) in optical lattices is studied by numerically solving the Gross-Pitaevskii equation. Our numerical results reproduce the self-trapping… Expand

Tunable Landau-Zener transitions in a spin-orbit-coupled Bose-Einstein condensate

- Physics
- 2014

The Landau-Zener (LZ) transition is one of the most fundamental phenomena in quantum dynamics. It describes nonadiabatic transitions between quantum states near an avoided crossing that can occur in… Expand