Magnetic‐TEGFET: Transistor Without a Gate

Abstract

Low-temperature current-voltage characteristics of n-type GaAs/GaAlAs quantum wells delta-doped in GaAs channel with Be acceptors are studied in the presence of a magnetic field. Negatively charged acceptor ions localize 2D conduction electrons by a combined effect of a quantum well and magnetic field parallel to the growth direction. In acceptor-doped samples, the Hall electric field plays the role of the gate voltage. It is shown that at magnetic fields as weak as 1.5 T (or higher), the drain current reaches a constant value independent of the drain voltage. This phenomenon is due to the electron localization resulting in the decrease of conducting electron density in the crossed-field configuration. The above special behavior of acceptor-doped GaAs/GaAlAs heterostructures is exploited to realize a device called Magnetic-TEGFET (Magnetic Two-dimensional Electron Gas Field Effect Transistor) operating at low temperatures. The elimination of the gate in the studied transistor suppresses the gate-to-drain leakage current, which, in the standard TEGFETs, results in the electronic shot noise.