0.4 0.5 0.6 0.7 0.8 E 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{E}$ L 0.4 0.5 0.6 0.7 0.8 E 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{E}$ L 0.5 1.0 1.5 2.0 2.5 3.0 3.5 E 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{E}$ L 0.5 1.0 1.5 2.0 2.5 3.0 3.5 E 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{E}$ L 0.4 0.6 0.8 1.0 1.2 1.4 1.6 W 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{W}$ L 0.4 0.6 0.8 1.0 1.2 1.4 1.6 W 0.0 0.2 0.4 0.6 0.8 1.0 $_{T}$H$_{W}$ L FIG. 2: Left, Transmission coefficient in the constant mass case. Right: plot of the transmission coefficient in the position dependent mass case. Parameters: a = 5, L = 10. Upper plots are for W = 1 . 2 and lower plots for W = 4 . 2. FIG. 3: Transmission coefficient as a function of the barrier height W . Left: in the constant mass case. Right: the position dependent mass case. Parameters: a = 5, L = 10, m$_{0}$ = 0 . 4 and E = 2 m$_{0}$ . IV. EFFECTIVE-MASS DIRAC EQUATION, BOUND STATES Let us study the bound states for the particle with position dependent mass. In order to do this we take the W-S potential with W → − W . 15