Condensate of a low dimensional charged Bose gas in a uniform magnetic field

G. A. Shul’man

A. S. Alexandrov, William H. Beere, V. V. Kabanov

Sang-Hoon Kim, Peter Pfeifer

The Bose condensation of a stack of low dimensional disks which is composed of a noninteracting charged Bose gas in a uniform magnetic field is studied. A statistical approach with density of states at noninteger dimensions are applied for the system. The condensate fraction of the disk system in a uniform magnetic field is calculated. The stack of low dimensional charged Bose disks is found not to share the condensate behavior of the traditional BCS superfluids.

A. K. Das

Brandon P. van Zyl, David A. W. Hutchinson

We present closed-form, analytical expressions for the thermodynamic properties of an ideal, two-dimensional (2D) charged Fermi or Bose gas in the presence of a uniform magnetic field of arbitrary strength. We consider both the homogeneous quantum gas (in which case our expressions are exact) and the inhomogeneous gas within the local-density approximation. Our results for the Fermi gas are relevant to the current-density-functional theory of low-dimensional electronic systems in magnetic fields. For a 2D charged Bose gas (CBG) in a homogeneous magnetic field, we show that the uniform system undergoes a sharp transition at a critical temperature ${T}_{c}^{\ensuremath{\star}},$ below which there is a macroscopic occupation of the lowest Landau level. An examination of the one-body density matrix, however, reveals the absence of long-range order, thereby indicating that the transition cannot be interpreted to a Bose-Einstein condensate. Nevertheless, for $T<{T}_{c}^{\ensuremath{\star}}$ and weak magnetic fields, the system still exhibits magnetic properties which are practically indistinguishable from those of a condensed, superconducting CBG. We therefore conclude that while a condensate is a sufficient condition for the ideal CBG to exhibit a superconducting state, it may not be a necessary condition.

Sanghoon Kim

A stack of disks with numerous holes composed of a non-interacting charged Bose gas is modeled as a low dimensional disk. The Bose condensation of the net-like disk system in a uniform magnetic field is studied. Calculation of the condensate fraction of the net-like disk system showed that there still exists a non-zero condensate fraction at low temperature and in weak field.