Plane two-barrier resonance-tunneling structures: Resonance energies and resonance widths of quasi-stationary electron states

摘要

A theory of resonance energies and widths of quasi-stationary states is suggested; this theory is based on the distribution function of the probability density for the location of an electron in a two-barrier resonance-tunneling structure, and on the use of a transfer matrix and an S scattering matrix in the models of rectangular and δ-shaped potentials with various effective masses in the layers of the nanosystem. With an In_(0.53)Ga_(0.47)As/In_(0.52)Al_(0.48)As nanosystem as an example, the evolution of spectral parameters of an electron's quasi-stationary states is analyzed in relation to geometric sizes of the resonance-tunneling structure; these states were calculated using three different methods. It is shown that, since the δ-barrier model overestimates the resonance width by several tens of times in comparison with a more realistic model of rectangular potentials, the former model can be only used for rough estimations.