Dynamics of double-barrier heterostructures with doped barriers

✍ Scribed by Lakshmi N. Pandey; Thomas F. George

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 433 KB
• Volume: 13
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1993.1082

✦ Synopsis

A time-dependent Schrödinger equation has been solved numerically for a doublebarrier and a quantum-well resonant tunnelling structure, with special emphasis on the system where barriers are doped specially by negative delta-function potentials ( (\delta)-potentials) which broaden the widths of the resonances and in turn decrease the dwell times. The strengths of the delta functions can be such that they may form bound states in the barrier regions, but the states bound to the (\delta)-potential are very shallow. For this study, the delta-function potentials are replaced by equivalent barriers of different heights and widths. It is found that for a certain strength of the (\delta)-potential or parametric value of the equivalence barriers in the barriers of the resonant tunneling structure, there are three resonance states very close together. The square of the wavefunctions trapped in the well region for the states oscillate in time for a broad wavepacket in (k)-space, whereas the wavefunction trapped in the whole structure decays exponentially. The oscillating part resembles the quantum beats.