Browse Prior Art Database

Quantum Well Transfer Device

IP.com Disclosure Number: IPCOM000048265D
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Heiblum, M: AUTHOR [+3]

Abstract

A real space transfer device is constructed which possesses a negative resistance controlled by the layer thickness, alloy composition and contact formation. Fig. 1 is a schematic of the device, and Fig. 2 is a schematic band diagram of the device.

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Quantum Well Transfer Device

A real space transfer device is constructed which possesses a negative resistance controlled by the layer thickness, alloy composition and contact formation. Fig. 1 is a schematic of the device, and Fig. 2 is a schematic band diagram of the device.

Layers are running parallel and into the plane of the illustration, and contacts are formed at the x-y plane as shown. Before applying an electric field (Epsilon=Epsilon1(z)), most electrons will occupy the first level of well d(2), which is wide enough and possesses a high mobility (assuming k(B) T much less than DeltaE). When a sufficiently strong electric field epsilon is applied, electrons can heat up to energies approximately delta (less than phono energy) and transfer via tunneling into the first level of well d(2). This potential well is designed to have a low mobility both due to its smaller thickness d(2) and its higher Al alloy content. Obviously, for epsilon less than epsilon(th), where epsilon(th) will suffice to heat up the electrons by DeltaE in a distance shorter than the mean free path, most electrons will be conducting in well d (1) with a high current. But for Epsilon Greater Than Epsilon(th), electron transfer will occur and the current which is collected from all layers will drop, resulting in a differential negative resistance.

The mobility in potential well d(1) can be controlled via: (a) Al concentration
(y), (b) thickness d(1), (c) doping in the well, and (d) in the...