980 research outputs found
Probing local electronic states in the quantum Hall regime with a side coupled quantum dot
We demonstrate a new method for locally probing the edge states in the
quantum Hall regime utilizing a side coupled quantum dot positioned at an edge
of a Hall bar. By measuring the tunneling of electrons from the edge states
into the dot, we acquire information on the local electrochemical potential and
electron temperature of the edge states. Furthermore, this method allows us to
observe the spatial modulation of the electrostatic potential at the edge state
due to many-body screening effect.Comment: 5 pages, 5 figure
Observation of "Partial Coherence" in an Aharonov-Bohm Interferometer with a Quantum Dot
We report experiments on the interference through spin states of electrons in
a quantum dot (QD) embedded in an Aharonov-Bohm (AB) interferometer. We have
picked up a spin-pair state, for which the environmental conditions are ideally
similar and have traced the AB amplitude in the range of the gate voltage that
covers the pair. The behavior of the asymmetry in the amplitude around the two
Coulomb peaks agrees with the theoretical prediction that relates a spin-flip
process in a QD to the quantum dephasing of electrons. These results consist
evidence of "partial coherence" due to an entanglement of spins in the QD and
the interferometer.Comment: 4 pages, 3 figures, RevTe
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