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

• Published in: Journal of applied physics 1990-12, Vol.68 (11), p.5724-5728
• Main Authors: PANDEY, L. N, GEORGE, T. F, RUSTGI, M. L, SAHU, D
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Surface and interface electron states
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.346966

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.