Phase Separation of a Fast Rotating Boson-Fermion Mixture in the Lowest-Landau-Level Regime

By minimizing the coupled mean-field energy functionals, we investigate the ground-state properties of a rotating atomic boson-fermion mixture in a two-dimensional parabolic trap. At high angular frequencies in the mean-field-lowest-Landau-level regime, quantized vortices enter the bosonic condensate, and a finite number of degenerate fermions form the maximum-density-droplet state. As the boson-fermion coupling constant increases, the maximum density droplet develops into a lower-density state associated with the phase separation, revealing characteristics of a Landau-level structure

Formation and decay dynamics of excitonic photoluminescence in a GaAs/AlGaAs superlattice under an electric field

Photoluminescence (PL) dynamics of localized excitons in a strongly coupled 40 Å/40 Å GaAs/Al0.2Ga0.8/As superlattice under an electric field along the growth direction is reported. At zero field, a delayed PL formation due to the relaxation of dark excitons into radiative states is observed. With increasing field, both the PL decay time and the PL amplitude are strongly reduced. A rate equation analysis of the measured PL transients gives evidence that the field‐induced dissociation of nonradiative excitons is important

Quantization with Action-Angle Coherent States

For a single degree of freedom confined mechanical system with given energy, we know that the motion is always periodic and action-angle variables are convenient choice as conjugate phase-space variables. We construct action-angle coherent states in view to provide a quantization scheme that yields precisely a given observed energy spectrum ${E_n}$ for such a system. This construction is based on a Bayesian approach: each family corresponds to a choice of probability distributions such that the classical energy averaged with respect to this probability distribution is precisely $E_n$ up to a constant shift. The formalism is viewed as a natural extension of the Bohr-Sommerfeld rule and an alternative to the canonical quantization. In particular, it also yields a satisfactory angle operator as a bounded self-adjoint operator

Diabetic cases controlled with low carbohydrate diet (LCD) and GLP-1 receptor agonist (GLP-1 RA)

Recent treatment for type 2 diabetes mellitus (T2DM) has included glucagon-like peptide-1 receptor agonist (GLP-1 RA), indicating clinical efficacy for better glucose variability. Subjects were seven patients with T2DM associated with the obese tendency. Their average age was 63.8 ± 21.7 years old (5 males, 2 females) who received a new administration of GLP-1 RA (Mean ± standard deviation). For GLP-1 RA, dulaglutide (TRULICITY R, single-dose pen) was administered by subcutaneous injection 0.75 mg once a week. Basal data at 0 month revealed that body weight 76.0 ± 11.6 kg, body mass index (BMI) 29.2 ± 11.6, blood C-peptide immunoreactivity (CPR) 2.68 ± 0.49 ng/mL, respectively. After the intervention of dulaglutide, decreased value of BMI for 3 and 6-9 months was 0.78 ± 0.45 and 1.16 ± 0.85, and HbA1c for 3 and 6-9 months was 1.60 ± 1.52% and 2.01 ± 1.44%, respectively. Though these cases have various complications besides T2DM, they showed clinical effects of weight reduction and lowering blood glucose. Diabetic treatment for current cases would suggest that GLP-1 RA would be effective in various situations such as a super-aged patient, medical practice in the remote area, family care and visiting nursing

Reflection of a Lieb-Liniger wave packet from the hard-wall potential

Nonequilibrium dynamics of a Lieb-Liniger system in the presence of the hard-wall potential is studied. We demonstrate that a time-dependent wave function, which describes quantum dynamics of a Lieb-Liniger wave packet comprised of N particles, can be found by solving an $N$-dimensional Fourier transform; this follows from the symmetry properties of the many-body eigenstates in the presence of the hard-wall potential. The presented formalism is employed to numerically calculate reflection of a few-body wave packet from the hard wall for various interaction strengths and incident momenta.Comment: revised version, improved notation, Fig. 5 adde

Split-merge cycle, fragmented collapse, and vortex disintegration in rotating Bose-Einstein condensates with attractive interactions

The dynamical instabilities and ensuing dynamics of singly- and doubly-quantized vortex states of Bose-Einstein condensates with attractive interactions are investigated using full 3D numerical simulations of the Gross-Pitaevskii equation. With increasing the strength of attractive interactions, a series of dynamical instabilities such as quadrupole, dipole, octupole, and monopole instabilities emerge. The most prominent instability depends on the strength of interactions, the geometry of the trapping potential, and deviations from the axisymmetry due to external perturbations. Singly-quantized vortices split into two clusters and subsequently undergo split-merge cycles in a pancake-shaped trap, whereas the split fragments immediately collapse in a spherical trap. Doubly-quantized vortices are always unstable to disintegration of the vortex core. If we suddenly change the strength of interaction to within a certain range, the vortex splits into three clusters, and one of the clusters collapses after a few split-merge cycles. The vortex split can be observed using a current experimental setup of the MIT group.Comment: 11 pages, 10 figure

Theory of Multidimensional Solitons

We review a number of topics germane to higher-dimensional solitons in Bose-Einstein condensates. For dark solitons, we discuss dark band and planar solitons; ring dark solitons and spherical shell solitons; solitary waves in restricted geometries; vortex rings and rarefaction pulses; and multi-component Bose-Einstein condensates. For bright solitons, we discuss instability, stability, and metastability; bright soliton engineering, including pulsed atom lasers; solitons in a thermal bath; soliton-soliton interactions; and bright ring solitons and quantum vortices. A thorough reference list is included.Comment: review paper, to appear as Chapter 5a in "Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment," edited by P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag