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Radiation-induced current in quantum wires with side-coupled nano-rings

Yuriy V. Pershin·Carlo Piermarocchi
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Abstract

Photocurrent generation is studied in a system composed of a quantum wire with side-coupled quantum rings. The current generation results from the interplay of the particular geometry of the system and the use of circularly polarized radiation. We study the energy-momentum conservation for optical transitions involving electrons moving forwards and backwards in the wire. Due to the lack of time-reversal symmetry in the radiation, the optical transitions depend on the direction of motion of the electrons, leading to a current at zero bias voltage. The photocurrent increases with the number of rings within a wide range of physical parameters. A weak non-linear dependence of the current in the number of rings, related to quantum interference effects, is also predicted. This geometry suggests a scalable method for the generation of sizeable photocurrents based on nanoscale components.

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Yuriy V. Pershin, Carlo Piermarocchi. 2006-10-25. Radiation-induced current in quantum wires with side-coupled nano-rings. https://doi.org/10.1103/physrevb.75.035326

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