Three-dimensional Dirac oscillator in a thermal bath
  The thermal properties of the three-dimensional Dirac oscillator are considered. The canonical partition function is determined, and the high-temperature limit is assessed. The degeneracy of energy levels and their physical implications on the main thermodynamic functions are analyzed, revealing that these functions assume values greater than the one-dimensional case. So that at high temperatures, the limit value of the specific heat is three times bigger. 
M. H. Pacheco, R. V. Maluf, C. A. S. Almeida, and R. R. Landim
hep-th