X-point tunneling in AlAs/GaAs double barrier heterostructures

• Published in: Solid-state electronics Vol. 32; no. 12; pp. 1513 - 1517
• Main Authors: Ting, D.Z.-Y., Jackson, M.K., Chow, D.H., Söderström, J.R., Collins, D.A., McGill, T.C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.12.1989; Elsevier Science
• 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
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/0038-1101(89)90266-9

The effect of X-point tunneling in AlAs-GaAs-AlAs double barrier heterostructures is studied numerically and experimentally. Numerical simulations are performed within the framework of the one-band Wannier orbital model, which allows for simulatneous descriptions of the Γ-point double barrier profile and the X-point double well profile. This model is used to illustrate the dynamics of the following processes: resonant tunneling via the X-point quasi-bound states, non-resonant tunneling through X-point continuum states, and resonant tunneling through Γ-X mixed quasi-bound states. X-point effects on the tunneling escape times of electrons initially localized in the GaAs quantum wells are examined theoretically, and found to be supported by the observation of a dramatic drop in the Γ-point-related quantum well photoluminescence intensity.