THEORY OF ROOM-TEMPERATURE QUANTIZED RESISTANCE STEPS IN ELECTROFORMED METAL A-SI-H METAL STRUCTURES

Previous work by Hajto et al. [J, Non-Cryst. Solids 137/138 (1991) 499 ; Phil. Mag. 66 (1991) 349], Yun et al. [Appl. Phys. Lett. 63 (1993) 2 493] and Jafar and Haneman [Phys. Rev. B 47 (1993) 10911] has suggeste d quantized electron transport at high temperature in amorphous silico n V-p(+)-Cr devices, A feature of transport in these devices is a sequ ence of steps in the resistance-voltage characteristic which seem to b e of integer or half integer multiples of h/2 e(2) Omega, the voltage at which such jumps occur is non-periodic. Such observations conflict with other forms of ballistic channels [J. Phys. C 60 (1998) 848] whic h show single jumps of h/2 e(2) Omega at periodic voltages. We present a simple model that shows that this difference arises as a natural co nsequence of having a two terminal geometry in which the applied elect ric field along the channel influences the number of conducting sub-ba nds instead of the electric field controlling the width of the channel .