Multipeak Kondo effect in one- and two-electron quantum dots.
We have fabricated a few-electron quantum dot that can be tuned down to zero electrons while maintaining strong coupling to the leads. Using a nearby quantum point contact as a charge sensor, we can determine the absolute number of electrons in the quantum dot. We find several sharp peaks in the differential conductance, occurring at both zero and finite source-drain bias, for the one- and two-electron quantum dot. We attribute the peaks at finite bias to a Kondo effect through excited states of the quantum dot and investigate the magnetic field dependence of these Kondo resonances.
Vidan
A
A
Division of Engineering and Applied Sciences and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Stopa
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M
Westervelt
R M
RM
Hanson
M
M
Gossard
A C
AC