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arXiv:cond-mat/0506005 · Europhysics Letters (EPL)

All-electronic coherent population trapping in quantum dots

B. Michaelis, Clive Emary, C. W. J. Beenakker

Published Feb 20, 2006• 112 citations
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Abstract

We present a fully electronic analogue of coherent population trapping in quantum optics, based on destructive interference of single-electron tunneling between three quantum dots. A large bias voltage plays the role of the laser illumination. The trapped state is a coherent superposition of the electronic charge in two of these quantum dots, so it is destabilized as a result of decoherence by coupling to external charges. The resulting current I through the device depends on the ratio of the decoherence rate Γ ϕ and the tunneling rates. For Γ ϕ → 0 one has simply I = e Γ ϕ . With increasing Γ ϕ the current peaks at the inverse trapping time. The direct relation between I and Γ ϕ can serve as a means of measuring the coherence time of a charge qubit in a transport experiment.

DOI
10.1209/epl/i2005-10458-6

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