Related papers: Phase slips driven by acoustic waves in Bose-Einst…
Orbital angular momentum (OAM) of light represents a fundamental optical freedom that can be exploited to manipulate quantum state of atoms. In particular, it can be used to realize spin-orbital-angular-momentum (SOAM) coupling in cold…
The burgeoning field of Bose-Einstein condensation in dilute alkali and hydrogen gases has stimulated a great deal of research into the statistical physics of weakly interacting quantum degenerate systems. The recent experiments offer the…
We investigate the effects of ellipticity-induced curvature on atomic Bose-Einstein condensates confined in quasi-one-dimensional closed-loop waveguides. Our theoretical study reveals intriguing phenomena arising from the interplay between…
Spontaneous pattern formation out of homogeneous media is one of the well-understood examples of hydrodynamic instabilities in classical systems, which naturally leads to the question of its manifestation in quantum fluids. Bose-Einstein…
We present a theoretical model for a transversally driven Bose-Einstein condensate coupled to an optical cavity. We focus on the interplay between different coherent couplings, which can trigger a structural phase transition, known as the…
We consider a Bose-Einstein condensate, which is confined in a very tight toroidal/annular trap, in the presence of a potential, which breaks the axial symmetry of the Hamiltonian. We investigate the stationary states of the condensate,…
Optical lattices are essential tools in ultra-cold atomic physics. Here we demonstrate theoretically that sub-wavelength confinement can be achieved in these lattices through superoscillations. This generic wave phenomenon occurs when a…
Early during the era of cosmic inflation, rotational invariance may have been broken, only later emerging as a feature of low-energy physics. This motivates ongoing searches for residual signatures of anisotropic space-time, for example in…
We investigate theoretically a topological vortex phase transition induced by a superradiant phase transition in an atomic Bose-Einstein condensate driven by a Laguerre-Gaussian optical mode. We show that superradiant radiation can either…
Surface modes in a Bose-Einstein condensate of sodium atoms have been studied. We observed excitations of standing and rotating quadrupolar and octopolar modes. The modes were excited with high spatial and temporal resolution using the…
We consider the topological defects and spin structures of spin-1 Bose-Einstein condensates (BECs) with spin-orbit coupling (SOC) and dipole-dipole interaction (DDI) in a rotating harmonic plus quartic trap. The combined effects of SOC, DDI…
We demonstrate a spatially resolved autocorrelation measurement with a Bose-Einstein condensate (BEC) and measure the evolution of the spatial profile of its quantum mechanical phase. Upon release of the BEC from the magnetic trap, its…
Equilibrium vortex formation in rotating binary Bose gases with a rotating frequency higher than the harmonic trapping frequency is investigated theoretically. We consider the system being evaporatively cooled to form condensates and a…
We consider a cavity optomechanical system consisting of a Bose-Einstein condensate (BEC) interacting with two counterpropagating traveling-wave modes in an optical ring cavity. In contrast to the more familiar case where the condensate is…
A quantum device for measuring two-body interactions, scalar magnetic fields and rotations is proposed using a Bose--Einstein condensate (BEC) in a ring trap. We consider an imbalanced superposition of orbital angular momentum modes with…
We investigate the hollowing transition of a shell-shaped Bose-Einstein condensate using collective excitations. The shell is created using an immiscible dual-species BEC mixture, with its hollowness controlled by tuning the repulsive…
Topological winding and unwinding in a quasi-one-dimensional metastable Bose-Einstein condensate are shown to be manipulated by changing the strength of interaction or the frequency of rotation. Exact diagonalization analysis reveals that…
We consider circular motion of a heavy object in an atomic Bose-Einstein condensate (BEC) at $T=0{\rm K}$. Even if the linear velocity of the object is smaller than the Landau critical velocity, the object may radiate quasiparticles and…
We study superfluid dissipation due to phase slips for a BEC flowing through a repulsive barrier inside a torus. The barrier is adiabatically raised across the annulus while the condensate flows with a finite quantized angular momentum. At…
We study the dynamics of a supersonically expanding ring-shaped Bose-Einstein condensate both experimentally and theoretically. The expansion redshifts long-wavelength excitations, as in an expanding universe. After expansion, energy in the…