Pf. Farinas et al., SUBBAND MIXING IN RESONANT MAGNETOTUNNELING THROUGH DOUBLE-BARRIER SEMICONDUCTOR NANOSTRUCTURES, Journal of applied physics, 79(11), 1996, pp. 8475-8481
We investigate subband mixing in the magnetotunneling of an electron t
hrough a double-barrier quantum dot. The fine structure in the current
-voltage characteristics, observed in a device formed by a quantum-dot
sandwiched by two quantum-wire contacts, is studied as a function of
a magnetic field applied along the direction of the tunneling current.
The increase of the magnetic field in this one-dimensional-zero-dimen
sional-one-dimensional tunneling process leads to a transition from a
low-field regime dominated by lateral confinement to a high-field regi
me dominated by magnetic confinement. The fine structure is shifted du
e to the magnetic field. The main result is that, as the magnetic fiel
d increases, the effect of the subband mixing at the interfaces become
s negligible and the fine structure tends to disappear at strong field
s. We provide a straightforward interpretation for the mechanism under
lying this transition and conjecture that it has the same origin as th
e one recently observed in a different device. (C) 1996 American Insti
tute of Physics.