Related papers: Second Quantized Landau Variables in the Case of D…
We use the Gross-Pitaevskii equation to determine the spatial structure of the condensate density of interacting bosons whose energy dispersion epsilon_k has two degenerate minima at finite wave-vectors q. We show that in general the…
Bose condensation of interacting bosons in a two-dimensional random potential is studied. The Gross-Pitaevskii equation is solved to determine the spatially-varying order parameter and the localization length as a function of the disorder,…
A large number of effects related to the phenomenon of Bose-Einstein Condensation (BEC) can be understood in terms of lowest order mean field theory, whereby the entire system is assumed to be condensed, with thermal and quantum…
We develop the multiscale technique to describe excitations of a Bose-Einstein condensate (BEC) whose characteristic scales are comparable with the healing length, thus going beyond the conventional hydrodynamical approximation. As an…
We propose a versatile variational method to investigate the spatio-temporal dynamics of one-dimensional magnetically-trapped Bose-condensed gases. To this end we employ a \emph{q}-Gaussian trial wave-function that interpolates between the…
We develop the dilute Bose gas model with random potential in order to understand the Bose system in random media such as 4He in porous glass. Using the random potential taking account of the pore size dependence, we can compare…
The ground state of bosonic atoms in a trap has been shown experimentally to display Bose-Einstein condensation (BEC). We prove this fact theoretically for bosons with two-body repulsive interaction potentials in the dilute limit, starting…
A homogeneous polarized dipolar Bose-Einstein condensate is considered in the presence of weak quenched disorder within mean-field theory at zero temperature. By first solving perturbatively the underlying Gross-Pitaevskii equation and then…
Traditional quantum hydrodynamics of Bose-Einstein condensates (BECs) is restricted by the continuity and Euler equations. It corresponds to the well-known Gross-Pitaevskii equation. However, the quantum Bohm potential, which is a part of…
The equivalence between neutral particles under rotation and charged particles in a magnetic field relates phenomena as diverse as spinning atomic nuclei, weather patterns, and the quantum Hall effect. In their quantum descriptions,…
A phenomenon of energy dissipation in Bose-Einstein condensates is studied based on a microscopic model for the motion of impurity. Critical velocities for onset of energy dissipation are obtained for periodic motions, such as a dipole-like…
We review how our current ideas about BEC developed in the early period 1925-1965, which had the specific goal of understanding superfluid $^4$He. This history is presented by commenting on the key contributions made by Einstein, Fritz…
Standard introductory modern physics textbooks do not exactly dwell on superfluidity in 4He. Typically, Bose-Einstein condensation (BEC) is mentioned in the context of an ideal Bose gas, followed by the statement that BEC happens in 4He and…
We have studied the hydrodynamic flow in a Bose-Einstein condensate stirred by a macroscopic object, a blue detuned laser beam, using nondestructive {\em in situ} phase contrast imaging. A critical velocity for the onset of a pressure…
In this article, we review the research on the dynamics of quantized vortices in superfluid helium and rotating Bose-Einstein condensates. First, after briefly reviewing the earlier research and describing the current problems on quantized…
Describing properties of a strongly interacting quantum many-body system poses a serious challenge both for theory and experiment. In this work, we study excitations of one-dimensional repulsive Bose gas for arbitrary interaction strength…
In the collisional region at finite temperatures, the collective modes of superfluids are described by the Landau two-fluid hydrodynamic equations. This region can now be probed over the entire BCS-BEC crossover in trapped Fermi superfluids…
We develop a model of a strongly correlated Bose fluid model in a confined potential for the purpose of analyzing the localization of Bose-Einstein condensation and the disappearance of superfluidity. This work is motivated by the recent…
The hydrodynamic equation of a spinor Bose-Einstein condensate (BEC) gives a simple description of spin dynamics in the condensate. We introduce the hydrodynamic equation of a ferromagnetic BEC with dissipation originating from the energy…
We present a method for evolving the projected Gross-Pitaevskii equation in an infinite rotating Bose-Einstein condensate, the ground state of which is a vortex lattice. We use quasi-periodic boundary conditions to investigate the behaviour…