The Wigner function of a semiconfined harmonic oscillator model with a position-dependent effective mass

Abstract

We propose a phase-space representation concept in terms of the Wigner function for a quantum harmonic oscillator model that exhibits the semiconfinement effect through its mass varying with the position. The new method is used to compute the Wigner distribution function exactly for such a semiconfinement quantum system. This method suppresses the divergence of the integrand in the definition of the quantum distribution function and leads to the computation of its analytical expressions for the stationary states of the semiconfined oscillator model. For this quantum system, both the presence and absence of the applied external homogenous field are studied. Obtained exact expressions of the Wigner distribution function are expressed through the Bessel function of the first kind and Laguerre polynomials. Furthermore, some of the special cases and limits are discussed in detail.

Figures (1)

• Figure 1: A comparative plot of the semiconfined quantum harmonic oscillator Wigner function (\ref{['wigfg0-2']}) of the ground state ($n=0$) without an external field ($g=0$, left plots) and with an external field ($g=2,\;4$; middle and right plots). Upper plots correspond to the confinement parameter $a=2$, whereas, middle plots correspond to the confinement parameter $a=4$ and lower plots correspond to the confinement parameter $a \to \infty$ ($m_0=\omega=\hbar=1$).