81 research outputs found
Damping of Josephson oscillations in strongly correlated one-dimensional atomic gases
We study Josephson oscillations of two strongly correlated one-dimensional
bosonic clouds separated by a localized barrier. Using a quantum-Langevin
approach and the exact Tonks-Girardeau solution in the impenetrable-boson
limit, we determine the dynamical evolution of the particle-number imbalance,
displaying an effective damping of the Josephson oscillations which depends on
barrier height, interaction strength and temperature. We show that the damping
originates from the quantum and thermal fluctuations intrinsically present in
the strongly correlated gas. Thanks to the density-phase duality of the model,
the same results apply to particle-current oscillations in a one-dimensional
ring where a weak barrier couples different angular momentum states
Single atom edge-like states via quantum interference
We demonstrate how quantum interference may lead to the appearance of robust
edge-like states of a single ultracold atom in a two-dimensional optical
ribbon. We show that these states can be engineered either within the manifold
of local ground states of the sites forming the ribbon, or of states carrying
one unit of angular momentum. In the former case, we show that the
implementation of edge-like states can be extended to other geometries, such as
tilted square lattices. In the latter case, we suggest to use the winding
number associated to the angular momentum as a synthetic dimension.Comment: 5 pages, 5 figure
Double barrier potentials for matter-wave gap solitons
We investigate collisions of solitons of the gap type, supported by a lattice
potential in repulsive Bose-Einstein condensates, with an effective
double-barrier potential that resembles a Fabry-Perot cavity. We identify
conditions under which the trapping of the entire incident soliton in the
cavity is possible. Collisions of the incident soliton with an earlier trapped
one are considered too. In the latter case, many outcomes of the collisions are
identified, including merging, release of the trapped soliton with or without
being replaced by the incoming one, and trapping of both solitons.Comment: 5 pages, 4 figure
Lattice solitons in quasicondensates
We analyze finite temperature effects in the generation of bright solitons in
condensates in optical lattices. We show that even in the presence of strong
phase fluctuations solitonic structures with well defined phase profile can be
created. We propose a novel family of variational functions which describe well
the properties of these solitons and account for the non-linear effects in the
band structure. We discuss also the mobility and collisions of these localized
wave packets.Comment: 4 pages, 2 figure
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