相关论文: Anisotropic dissipation of superfluid flow in a pe…
Two intersecting laser beams can produce a spatially-periodic coupling between two components of an atomic gas and thereby modify the dispersion relation of the gas according to a dressed-state formalism. Properties of a Bose-Einstein…
We present transport measurements on a dipolar superfluid using a Bose-Einstein condensate of Dy-162 with strong magnetic dipole-dipole interactions. By moving an attractive laser beam through the condensate we observe an anisotropy in…
We analyze the dynamics of a dilute, trapped Bose-condensed atomic gas coupled to a diatomic molecular Bose gas by coherent Raman transitions. This system is shown to result in a new type of `superchemistry', in which giant collective…
In this work, we discuss the Landau's criterion for anisotropic superfluidity. To this end, we consider a point-like impurity moving in a uniform Bose-Einstein condensate with either interparticle dipole-dipole interaction or Raman induced…
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 which turns out to be a function of the…
By calculating the density response function we identify the excitation spectrum of a Bose-Einstein condensate with equal Rashba and Dresselhaus spin-orbit coupling. We find that the velocity of sound along the direction of spin-orbit…
We report the direct observation of resistive flow through a weak link in a weakly interacting atomic Bose-Einstein condensate. Two weak links separate our ring-shaped superfluid atomtronic circuit into two distinct regions, a source and a…
We study the superfluid character of a dipolar Bose-Einstein condensate (DBEC) in a quasi-two dimensional (q2D) geometry. In particular, we allow for the dipole polarization to have some non-zero projection into the plane of the condensate…
Phase transitions can modify quantum behaviour on mesoscopic scales and give access to new and unusual quantum dynamics. Here we investigate the superfluid properties of a rotating two-component Bose--Einstein condensate as a function of…
We observed the expansion of vortex-free Bose-condensates after their sudden release from a slowly rotating anisotropic trap. Our results show clear experimental evidence of the irrotational flow expected for a superfluid. The expansion…
We explore the many body physics of a Bose condensed atom gas at finite temperature through the Raman transition between two hyperfine levels. Unlike the Bragg scattering where the phonon-like nature of the collective excitations has been…
We have created a long-lived (~ 40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier creates a tunable weak link in the condensate circuit, which can affect the current…
Multistep Bose-Einstein condensation of an ideal Bose gas in anisotropic harmonic atom traps is studied. In the presence of strong anisotropy realized by the different trap frequency in each direction, finite size effect dictates a series…
We theoretically study homogeneously trapped atomic Bose-Einstein condensates where all three momentum components couple to a pseudo-spin-$1/2$ degree of freedom. Tuning the anisotropies of spin-orbit coupling and the spin-dependent…
We investigate the dynamics of a Bose-Einstein condensate interacting with two non-interfering and counterpropagating modes of a ring resonator. Superfluid, supersolid and dynamic phases are identified experimentally and theoretically. The…
Motivated by recent experiments, we theoretically study a gas of atomic bosons confined in an elliptical harmonic trap; forming a quasi-two-dimensional atomic Bose-Einstein condensate subject to a density-dependent gauge potential which…
We study dissipation in a dilute Bose gas induced by the motion of a macroscopic object. A blue-detuned laser beam focused on the center of a trapped gas of sodium atoms was scanned both above and below the BEC transition temperature. The…
We study theoretically and experimentally the emergence of supersolid properties in a dipolar Bose-Einstein condensate. The theory reveals a ground state phase diagram with three distinct regimes - a regular Bose-Einstein condensate,…
A spatially inhomogeneous, trapped two-component Bose-Einstein condensate of cold atoms in the phase separation mode has been numerically simulated. It has been demonstrated for the first time that the surface tension between the components…
We have studied the hydrodynamic flow in a Bose-Einstein condensate stirred by a macroscopic object, a blue detuned laser beam, using nondestructive {\em in situ} phase contrast imaging. A critical velocity for the onset of a pressure…