278 research outputs found
Two-body and three-body contacts for three bosons in the unitary regime: Analytic expressions and limiting forms
The two and three-body contacts are central to a set of univeral relations
between microscopic few-body physics within an ultracold Bose gas and its
thermodynamical properties. They may also be defined in trapped few-particle
systems, which is the subject of this work. In this work, we focus on the
unitary three-body problem in a trap, where interactions are as strong as
allowed by quantum mechanics. We derive analytic results for the two and
three-body contacts in this regime and compare with existing limiting
expressions and previous numerical studies.Comment: 11 pages, 2 figures, Atoms special issue "Few-body Physics in
Ultracold Quantum Gases
Dynamics of three-body correlations in quenched unitary Bose gases
We investigate dynamical three-body correlations in the Bose gas during the
earliest stages of evolution after a quench to the unitary regime. The
development of few-body correlations is theoretically observed by determining
the two- and three-body contacts. We find that the growth of three-body
correlations is gradual compared to two-body correlations. The three-body
contact oscillates coherently, and we identify this as a signature of Efimov
trimers. We show that the growth of three-body correlations depends
non-trivially on parameters derived from both the density and Efimov physics.
These results demonstrate the violation of scaling invariance of unitary
bosonic systems via the appearance of log-periodic modulation of three-body
correlations
On the Appearance of Families of Efimov States in the Spinor Three-Body Problem
Few-body systems with access to multiple internal levels exhibit richness
beyond that typically found in their single-level counterparts. One example is
that of Efimov states in strongly-correlated spinor three-body systems. In [V.
E. Colussi, C. H. Greene, and J. P. D'Incao, Phys. Rev. Lett. {\bf 113}, 045302
(2014)] this problem was analyzed for spinor condensates finding a complex
level structure as in an early work [Bulgac and Efimov, Sov. J. Nucl. Phys. 22,
153 (1976)] in nuclear physics, and the impact of Efimov physics on the general
form of the scattering observables was worked out. In this paper we discuss the
appearance of novel families of Efimov states in the spinor three-body problem.Comment: Conference proceedings for the 21st International Conference on
Few-Body Problems in Physic
Undamped nonequilibrium dynamics of a nondegenerate Bose gas in a 3D isotropic trap
We investigate anomalous damping of the monopole mode of a non-degenerate 3D
Bose gas under isotropic harmonic confinement as recently reported by the JILA
TOP trap experiment [D. S. Lob- ser, A. E. S. Barentine, E. A. Cornell, and H.
J. Lewandowski (in preparation)]. Given a realistic confining potential, we
develop a model for studying collective modes that includes the effects of
anharmonic corrections to a harmonic potential. By studying the influence of
these trap anharmonicities throughout a range of temperatures and collisional
regimes, we find that the damping is caused by the joint mechanisms of
dephasing and collisional relaxation. Furthermore, the model is complimented by
Monte Carlo simulations which are in fair agreement with data from the JILA
experiment.Comment: 11 pages, 6 figure
Scattering hypervolume for ultracold bosons from weak to strong interactions
The elastic scattering properties of three bosons at low energy enter the
many-body description of ultracold Bose gases via the three-body scattering
hypervolume . We study this quantity for identical bosons that interact via
a pairwise finite-range potential. Our calculations cover the regime from
strongly repulsive potentials towards attractive potentials supporting multiple
two-body bound states and are consistent with the few existing predictions for
. We present the first numerical confirmation of the universal predictions
for in the strongly interacting regime, where Efimov physics dominates, for
a local nonzero-range potential. Our findings highlight how is influenced
by three-body quasibound states with strong -wave or -wave
characteristics in the weakly interacting regime.Comment: 13 pages, 8 figure
- …