2005/06/30 by B. Michaelis, Clive Emary, C. Emary +1
Computer Science · Physics and Astronomy · #Atomic physics #Charge (physics) #Charge qubit #Coherence (philosophical gambling strategy) #Condensed matter physics #Electron #Phase qubit #Physics #Population #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum decoherence #Quantum dot #Quantum mechanics #Quantum optics and atomic interactions #Quantum superposition #Quantum tunnelling #Qubit #Superposition principle #Trapping #cond-mat.mes-hall
paper · pdf · doi:10.1209/epl/i2005-10458-6
published as Europhys. Lett. 73, 677 (2006). · version 2: added results for unequal tunnel/decoherence rates
arxiv created 2006/01/10 · openalex publication_date 2006/02/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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.