Two-step condensation of the ideal Bose gas in highly anisotropic traps
نویسندگان
چکیده
The ideal Bose gas in a highly anisotropic harmonic potential is studied. It is found that BoseEinstein condensation occurs in two distinct steps as the temperature is lowered. In the first step the specific heat shows a sharp feature, but the system still occupies many one-dimensional quantum states. In the second step, at a significantly lower temperature, the ground state becomes macroscopically occupied. It should be possible to verify these predictions using present-day atom traps. The twostep behavior can occur in a rather general class of anisotropic traps, including the box potential. [S0031-9007(97)03666-1]
منابع مشابه
On Multistep Bose-Einstein Condensation in Anisotropic Traps
Multistep Bose-Einstein condensation of an ideal Bose gas in anisotropic harmonic atom traps is studied. In the presence of strong anisotropy realized by the different trap frequency in each direction, finite size effect dictates a series of dimensional crossovers into lower-dimensional excitations. Two-step condensation and the dynamical reduction of the effective dimension can appear in three...
متن کاملMulti-step Bose-Einstein Condensation of Trapped Ideal Bose Gases
The Phenomenon of multi-step Bose-Einstein condensation (BEC) of a finite number of non-interacting bosons in anisotropic traps has been demonstrated by studing the populations on eight subsets of states. The cusp in the specific heat is found to be associated with the crossover between subsets of states involving Bose functions gn(z) of different classes, as specified by their behaviour at z =...
متن کاملSuperfluid transition of homogeneous and trapped two-dimensional Bose gases.
Current experiments on atomic gases in highly anisotropic traps present the opportunity to study in detail the low temperature phases of two-dimensional inhomogeneous systems. Although, in an ideal gas, the trapping potential favors Bose-Einstein condensation at finite temperature, interactions tend to destabilize the condensate, leading to a superfluid Kosterlitz-Thouless-Berezinskii phase wit...
متن کاملFrom number theory to statistical mechanics: Bose–Einstein condensation in isolated traps
We question the validity of the grand canonical ensemble for the description of Bose–Einstein condensation of small ideal Bose gas samples in isolated harmonic traps. While the ground state fraction and the specific heat capacity can be well approximated with the help of the conventional grand canonical arguments, the calculation of the fluctuation of the number of particles contained in the co...
متن کاملThe second critical density and anisotropic generalised condensation
In this letter we discuss the relevance of the 3D Perfect Bose gas (PBG) condensation in extremely elongated vessels for the study of anisotropic condensate coherence and the “quasi-condensate”. To this end we analyze the case of exponentially anisotropic (van den Berg) boxes, when there are two critical densities ρc < ρm for a generalised Bose-Einstein Condensation (BEC). Here ρc is the standa...
متن کامل