UNITY RESONANCE AND UNDER-UNITY RESONANCE CONDITIONS IN ASYMMETRICAL DOUBLE-BARRIER STRUCTURES

Abstract

Resonant tunneling is studied theoretically in asymmetrical double-barrier structures with arbitrary potential profile. Analytical expressions of the transmission coefficient and resonance condition are derived by taking into account the mass difference between the well and barrier layers. It is confirmed that resonant tunneling with unity resonant transmission or under-unity resonant transmission may occur in asymmetrical double-barrier structures. Two independent conditions are required for unity resonant transmission: one is the Phase Difference Condition for Resonance (PDCR) and the other is the Maximum Condition for the Peak Value (MCPV). The under-unity resonant transmission occurs when only PDCR holds. Furthermore, wave functions of an electron at resonance level are calculated and the confining phenomenon is studied.