We have measured the critical atom number in a harmonically trapped two-dimensional (2D) Bose gas of rubidium atoms at different temperatures. We found this number to be about five times higher than predicted by the semi-classical theory of Bose-Einstein condensation (BEC) in the ideal gas. This demonstrates that the conventional BEC picture is inapplicable in an interacting 2D atomic gas, in s...

We have studied the transition from two to three dimensions in a low temperature weakly interacting 6Li Fermi gas. Below a critical atom number N(2D) only the lowest transverse vibrational state of a highly anisotropic oblate trapping potential is occupied and the gas is two dimensional. Above N(2D) the Fermi gas enters the quasi-2D regime where shell structure associated with the filling of in...

We investigate the evolution of the interaction of the magnetoplasmon resonance with the harmonics of the cyclotron resonance as the confinement of an electron gas in a quantum wire increasingly deviates from the parabolic case. The occurrence of the Bernstein modes is observed in a time-dependent Hartree model of a two-dimensional electron gas in a single quantum wire.

The femtosecond inter-Landau-level dynamics of a two-dimensional electron gas in a large magnetic field is investigated by degenerate four-wave mixing on modulation doped quantum wells. We observe a large transfer of oscillator strength to the lowest Landau level, and unusual dynamics due to Coulomb correlation. We interpret the effects using a model based on shakeup of the electron gas.

We study the anomalous Hall conductivity in spin-polarized, asymmetrically confined two-dimensional electron and hole systems, taking into account the intrinsic, side-jump, and skew-scattering contributions to the transport. We find that the skew scattering, principally responsible for the extrinsic contribution to the anomalous Hall effect, vanishes for the two-dimensional electron system if b...

We present a comprehensive discussion of the ground-state properties dilute D-dimensional Bose gas interacting with few static impurities. Assuming short-ranged character boson-impurity interaction, we calculated energy three- and two-dimensional systems one two impurities immersed.

In this paper, we study the electronic properties of a concentric triple quantum ring using exact diagonalization technique. The energy spectra and magnetization for a single electron and two electrons, in the presence of an applied magnetic field, are calculated and discussed. It is shown that, for two-interacting electrons, the period of Aharonov-Bohm oscillations decreases to the half of tha...

A linear response theory is provided for the dynamic interaction effects of an electron soliton confined in semiconductor quantum well with a conducting surface or a two-dimensional electron gas. It is shown that the soliton-electron-gas effective potential contains a dissipative component resisting against changes of the soliton charge density. Due to the energy dissipation moving solitons are...