Resonant tunneling and negative differential resistance in a variably spaced superlattice energy filter

Abstract
Resonant tunneling is reported for the first time in a series of variably spaced AlGaAs/GaAs multiple quantum well structures in which the levels in adjacent quantum wells are brought into alignment by an applied bias. Resonant tunneling and negative differential resistance effects are observed for two- and three-well structures designed for electron injection at voltages between 0.1 and 0.2 V.