2 research outputs found
Spin selective Aharonov-Bohm oscillations in a lateral triple quantum dot
We present a theory for spin selective Aharonov-Bohm oscillations in a
lateral triple quantum dot. We show that to understand the Aharonov-Bohm (AB)
effect in an interacting electron system within a triple quantum dot molecule
(TQD) where the dots lie in a ring configuration requires one to not only
consider electron charge but also spin. Using a Hubbard model supported by
microscopic calculations we show that, by localizing a single electron spin in
one of the dots, the current through the TQD molecule depends not only on the
flux but also on the relative orientation of the spin of the incoming and
localized electrons. AB oscillations are predicted only for the spin singlet
electron complex resulting in a magnetic field tunable "spin valve".Comment: 4 pages, 4 figure
Theory of electronic transport through a triple quantum dot in the presence of magnetic field
Theory of electronic transport through a triangular triple quantum dot
subject to a perpendicular magnetic field is developed using a tight binding
model. We show that magnetic field allows to engineer degeneracies in the
triple quantum dot energy spectrum. The degeneracies lead to zero electronic
transmission and sharp dips in the current whenever a pair of degenerate states
lies between the chemical potential of the two leads. These dips can occur with
a periodicity of one flux quantum if only two levels contribute to the current
or with half flux quantum if the three levels of the triple dot contribute. The
effect of strong bias voltage and different lead-to-dot connections on
Aharonov-Bohm oscillations in the conductance is also discussed