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 forward 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 nonlinear 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.
Published in Physical Review B, ed. Gene D. Sprouse, Volume 75, Issue 3, 2007, pages 035326-1-035326-6.
Pershin, Y. V., & Piermarochhi, C. (2007). Radiation-induced current in quantum wires with side-coupled nanorings. Physcial Review B, 75(3), 035326-1 - 035326-6. DOI: 10.1103/PhysRevB.75.035326
© Physical Review B, 2007, American Physical Society