Electronic and transport properties of anisotropic semiconductor quantum wires
S. M. Cunha, D. R. da Costa, Levi C. Felix, Andrey Chaves, J. Milton Pereira
Abstract
Within the effective-mass approximation, we theoretically investigated the electronic and transport properties of 2D semiconductor quantum wires (QWs) with anisotropic effective masses and different orientations with respect to the anisotropic axis. The energy levels in the absence and presence of an external magnetic field are analytically calculated, showing (i) a strong dependence on the spacing of energy levels related to the alignment QW angle and the anisotropy axis, and (ii) for non-null magnetic fields, the quantum Hall edge states are significantly affected by the edge orientation. Moreover, by means of the split-operator technique, we analyzed the time evolution of wave packets in straight and V-shaped anisotropic QWs and compared the transmission probabilities with those of isotropic systems. In the anisotropic case, we found damped oscillations in the average values of velocity in both $x$ and $y$ directions for a symmetric Gaussian wave packet propagating along a straight wide QW, with the oscillation being more evident as the noncollinearity between the group velocity and momentum vectors increases.