Photon-Assisted Tunneling Through a Quantum Dot: Theory and Experiment
We have studied the effect of microwaves on Coulomb blockade devices, both theoretically and experimentally. Our model extends the Tien-Gordon theory for photon-assisted tunneling to encompass the correlated tunneling of electrons through small capacitance double-junction devices. The main theoretical results for a double-junction system are (1) the prediction of sharp current jumps reflecting the discrete photon energy hf in current-gate voltage characteristics and (2) the prediction of a zero-bias current whose sign changes when an electron is added to the island between the junctions. Preliminary measurements are presented on split-gate quantum dots with 19 GHz microwaves applied to one of the control gates. The observed photoresponse is in good agreement with the predictions of the model.
KeywordsGate Voltage Tunnel Junction Tunnel Rate Current Jump Coulomb Oscillation
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