Cotunneling spectroscopy in few-electron quantum dots.
Few-electron quantum dots are investigated in the regime of strong tunneling to the leads. Inelastic cotunneling is used to measure the two-electron singlet-triplet splitting above and below a magnetic field driven singlet-triplet transition. Evidence for a nonequilibrium two-electron singlet-triplet Kondo effect is presented. Cotunneling allows orbital correlations and parameters characterizing entanglement of the two-electron singlet ground state to be extracted from dc transport.
Zumbühl
D M
DM
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Marcus
C M
CM
Hanson
M P
MP
Gossard
A C
AC