13,737 research outputs found
Elastic Multi-Body Interactions on a Lattice
We show that by coupling two hyperfine states of an atom in an optical
lattice one can independently control two-, three-, and four-body on-site
interactions in a non-perturbative manner. In particular, under typical
conditions of current experiments one can have a purely three- or four-body
interacting gas of K atoms characterized by on-site interaction shifts
of several 100Hz.Comment: 6 pages, 3 figure
Three-Body Interacting Bosons in Free Space
We propose a method of controlling two- and three-body interactions in an
ultracold Bose gas in any dimension. The method requires us to have two coupled
internal single-particle states split in energy such that the upper state is
occupied virtually but amply during collisions. By varying system parameters
one can switch off the two-body interaction while maintaining a strong
three-body one. The mechanism can be implemented for dipolar bosons in the
bilayer configuration with tunnelling or in an atomic system by using
radio-frequency fields to couple two hyperfine states. One can then aim to
observe a purely three-body-interacting gas, dilute self-trapped droplets, the
paired superfluid phase, Pfaffian state, and other exotic phenomena.Comment: Published version with Supplemental Materia
Ultradilute low-dimensional liquids
We calculate the energy of one- and two-dimensional weakly interacting
Bose-Bose mixtures analytically in the Bogoliubov approximation and by using
the diffusion Monte Carlo technique. We show that in the case of attractive
inter- and repulsive intraspecies interactions the energy per particle has a
minimum at a finite density corresponding to a liquid state. We derive the
Gross-Pitaevskii equation to describe droplets of such liquids and solve it
analytically in the one-dimensional case.Comment: published version + supplemental materia
Propagation of a Dark Soliton in a Disordered Bose-Einstein Condensate
We consider the propagation of a dark soliton in a quasi 1D Bose-Einstein
condensate in presence of a random potential. This configuration involves
nonlinear effects and disorder, and we argue that, contrarily to the study of
stationary transmission coefficients through a nonlinear disordered slab, it is
a well defined problem. It is found that a dark soliton decays algebraically,
over a characteristic length which is independent of its initial velocity, and
much larger than both the healing length and the 1D scattering length of the
system. We also determine the characteristic decay time.Comment: 4 pages, 2 figure
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