T. Figielski et al., QUANTUM INTERFERENCE OF ELECTRONS TRANSMITTED THROUGHOUT A DOUBLE-BARRIER RESONANT-TUNNELING STRUCTURE UNDER A PERPENDICULAR MAGNETIC-FIELD, Semiconductor science and technology, 12(1), 1997, pp. 86-90
Recently, we have discovered a fine oscillatory structure (FOS) of the
current flowing through resonant tunnelling devices consisting basica
lly of two very thin AlAs barriers separated by a GaAs quantum well. I
n this work we have found two striking properties of FOS in a magnetic
field applied normally to the current flow: (i) a phase shift of the
FOS on the bias-voltage scale which is proportional to the squared ind
uction of the magnetic field; (ii) rapid oscillatory-type fall-off in
FOS amplitude with increasing magnetic field. We demonstrate, using a
simple quantitative model, that both properties can be consistently ex
plained in terms of quantum interference between electrons which escap
ed from the quantum well and those partly reflected at a potential ste
p on the collector side of the device. The physical conditions necessa
ry for the appearance of FOS are discussed.