Coherent Quantum Ratchets Driven by Tunnel Oscillations

Abstract

We demonstrate that the tunnel oscillations of a biased double quantum dot can be employed as driving source for a quantum ratchet. As a model, we use two capacitively coupled double quantum dots. One double dot is voltage biased and provides the ac force, while the other experiences the ac force and acts as coherent quantum ratchet. The current is obtained from a Bloch-Redfield master equation which ensures a proper equilibrium limit. We find that the two-electron states of the coupled ratchet-drive Hamiltonian lead to unexpected steps in the ratchet current.

4 pages, 4 figures

References in corpus (10)

• Artificial Brownian motors: Controlling transport on the nanoscale
• Frequency-selective single photon detection using a double quantum dot
• Using a quantum dot as a high-frequency shot noise detector
• A double-dot quantum ratchet driven by an independently biased quantum point contact
• Mesoscopic Coulomb drag, broken detailed balance and fluctuation relations
• Quantum ratchet effect for vortices
• Telegraph Noise in Coupled Quantum Dot Circuits Induced by a Quantum Point Contact
• Backaction of a charge detector on a double quantum dot
• Shot noise in non-adiabatically driven nanoscale conductors
• Charge ratchet from spin flip: space-time symmetry paradox

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• Capacitively coupled nano conductors: Ratchet currents and exchange fluctuation relations
• Amplification of quantum transfer and quantum ratchet
• Cross correlations in mesoscopic charge detection