Evidence of Bose-Einstein Condensation in an Atomic Gas with Attractive Interactions

Abstract

[14]. The atoms are confined in a magnetic trap that is produced by six permanent magnet cylinders. The magnets are arranged to produce a minimum at the trap center near which the field strength varies quadratically.

Vortices in a trapped dilute Bose-Einstein condensate

“…The recent dramatic achievement of Bose-Einstein condensation in trapped alkali-metal gases at ultra-low temperatures [1][2][3] has stimulated intense experimental and theoretical activity. The atomic Bose-Einstein condensates (BECs) differ fundamentally from the helium BEC in several ways.…”

One- and two-dimensional Bose-Einstein condensation of atoms in dark magneto-optical lattices

“…For an atomic sample with the density n ∼ 10 11 − 10 12 cm −3 and with the size L ∼ 10 −1 cm we have N ∼ 10 5 − 10 6 for each plane at the periodicity about 10 −4 cm. Then for a confining potential with f ∼ 10 3 Hz the transition temperature T c ∼ 10 −5 K is in few orders higher than the transition temperature in 3D magnetic traps [1][2][3]. In the case under consideration BEC can be observed, for instance, by the time-of-flight measurements of the atomic momentum distribution after turning off of a confining potential.…”

“…After the outstanding experiments on Bose-Einstein condensation (BEC) of an atomic gas in a magnetic trap [1][2][3] studies of phenomenon originated from quantum statistics of particles became one of the main subjects in contemporary atomic physics. Achieving of BEC by optical means is of especial interest [4][5][6][7].…”

“…It is worth noting, that in the refs. [1][2][3] laser fields play an auxiliary role and they are used for precooling down to sufficiently low temperatures with successive evaporating cooling in a magnetic trap, when in the final stage of experiments optical fields are absent and the main part of atoms escape from a trap under evaporative cooling. One of the main components of the optical methods [4,6] is the formation of a non-dissipative optical or magneto-optical potential, when atoms scatter photons with very low rates.…”

Stability of trapless Bose–Einstein condensates with two- and three-body interactions

“…Bose-Einstein condensates (BECs) first realized experimentally in 1995 for rubidium [1], lithium [2,3], and sodium [4], provide unique opportunities for exploring quantum phenomena on a macroscopic scale. The properties of a condensate at absolute zero temperature are usually described by the time-dependent, nonlinear, mean-field GrossPitaevskii (GP) equation [5].…”