D. Sahu

Change in density of states in a resonant tunneling structure due to a scattering center in the well

The change in density of states and transmission resonance energy shifts have been calculated for a double‐barrier single‐quantum‐well heterostructure by placing a scattering center in the middle of the well and representing it by (1) a thin barrier of variable height and fixed width or (2) a delta‐function potential of variable strength. It is found that the energies of the even‐resonance states shift towards the higher energies and states get broader as the height of the thin barrier increases. Similar behavior is observed for the delta‐function potential as the strength of the delta‐function potential increases. The peak value of the density of states versus energy plot are reduced for even resonance states due to the broadening of these states. The physical processes related with these behavior are discussed. Moreover, there are no changes in the odd‐resonance states because of the nature of their wave functions in the well region of the resonant tunneling structure.

Width anomaly in resonant tunneling structures

We have found anomalous behavior in the variation of width and position of the resonance as a function of the effective mass Hamiltonian parameter. This is an addendum to our previous paper, Solid State Communications 72, 7 (1989).