Related papers: Monitoring currents in cold-atom circuits
We study the states of one and two atoms in a rotating ring lattice in a Hubbard type tight-binding model. The model is developed carefully from basic principles in order to properly identify the physical observables. The one-particle…
We have studied the internal and external dynamics of a Bose-Einstein condensate in an anharmonic magnetic waveguide. An oscillating condensate experiences a strong coupling between the center of mass motion and the internal collective…
In this work, we would like to present the Bose-Einstein Condensation in such a system where rotation is decreasing radially from the centre of the condensate. That non-uniform rotation is defined by a rotating parameter called $\lambda$.…
In this article, we describe an experimental system for generating Bose-Einstein condensates and controlling the shape and motion of the condensate by using miniaturised magnetic potentials. In particular, we describe the magnetic trap…
We observe solitonic vortices in an atomic Bose-Einstein condensate after free expansion. Clear signatures of the nature of such defects are the twisted planar density depletion around the vortex line, observed in absorption images, and the…
The local current flow through three small aromatic carbon molecules, namely benzene, naphthalene and anthracene, is studied. Applying density functional theory and the non-equilibrium Green's function method for transport, we demonstrate…
The effect of an additional quasi-resonant drive on the dynamics of the ring-shaped incoherently pumped polariton condensates carrying angular momentum (vorticity) is studied theoretically. Numerical simulations of the 2D and 1D…
We examine a Bose-Einstein condensate of atoms that rotates in a quadratic-plus-quartic potential. It is shown that states of different circulation can be metastable. As a result, we demonstrate that the gas can exhibit hysteresis as the…
We theoretically investigate an adjustable-radius magnetic storage ring for laser-cooled and Bose-condensed atoms. Additionally, we discuss a novel time-dependent variant of this and other ring traps. Time-orbiting ring traps provide a high…
We have succeded in creating Bose-Einstein condensates with 2 million sodium atoms in a '4D' magnetic trap. We show the dynamic formation of a condensate as evaporative cooling proceeds. We also present a series of trap-release pictures…
We demonstrate the use of a ring-shaped Bose-Einstein condensate as a rotation sensor by measuring the interference between two counter-propagating phonon modes imprinted azimuthally around the ring. We observe rapid decay of the…
We consider a trapped Bose--Einstein condensate (BEC) with a highly quantized vortex. For the BEC with a doubly, triply or quadruply quantized vortex, the numerical calculations have shown that the Bogoliubov--de Gennes equations, which…
Tunneling of atoms between two trapped Bose-condensed gases at finite temperatures is explored using a many-body linear response tunneling formalism similar to that used in superconductors. To lowest order, the tunneling currents can be…
We study interacting bosons in optical lattices in the weak-tunneling regime in systems that exhibit the coexistence of Mott-insulating and condensed phases. We discuss the nature of the condensed ground state in this regime and the…
A repulsively interacting Bose-Einstein condensate on a ring is well known to show persistent currents. For attractive interactions, however, a bound state may form that renders the rotation classical. Here we show that in a…
We present the design of a ring exchange interaction in cold atomic gases subjected to an optical lattice using well understood tools for manipulating and controlling such gases. The strength of this interaction can be tuned independently…
We investigate the rotational properties of quantum droplets, which form in a mixture of two Bose-Einstein condensates, in the presence of an anharmonic trapping potential. We identify various phases as the atom number and the angular…
We theoretically analyze the cooling dynamics of an atom which is tightly trapped inside a high-finesse optical resonator. Cooling is achieved by suitably tailored scattering processes, in which the atomic dipole transition either scatters…
Various widely-used mean-field type theories for a dilute Bose gas are critically examined in the light of the recent discovery of Bose-Einstein condensation of atomic gases in a confined geometry. By numerically solving the mean-field…
We numerically study the dynamics of a spinor chromium condensate in low magnetic fields. We show that the condensate evolution has a resonant character revealing rich structure of resonances similar to that already discussed in the case of…