Resonant tunneling through one- and zero-dimensional states constricted by AlxGa1-xAs/GaAs/AlxGa1-xAs heterojunctions and high-resistance regions induced by focused Ga ion-beam implanation.

Abstract

Lateral dimensions of ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/GaAs double-barrier diodes were restricted by use of focused Ga ion-beam implantation. The diode with a restricted lateral dimension exhibited a series of resonant-tunneling current peaks corresponding to the laterally confined one-dimensional levels superimposed on to the ground state confined by the heterojunctions. The resonant peaks were more pronounced in the diode with the smaller lateral dimension and consequently stronger lateral confinement. The spectral feature of the resonant peaks suggests mixing of even- (odd-) parity one-dimensional subbands in the double-barrier structure with two-dimensional subbands of the same parity in the contact. The diode with two restricted lateral dimensions also exhibited a series of resonant peaks corresponding to the laterally confined zero-dimensional levels.