Magnetically induced pumping and memory storage in quantum rings
arXiv:1112.0140 · doi:10.1103/PhysRevB.84.245201
Abstract
Nanoscopic rings pierced by external magnetic fields and asymmetrically connected to wires behave in sharp contrast with classical expectations. By studying the real-time evolution of tight-binding models in different geometries, we show that the creation of a magnetic dipole by a bias-induced current is a process that can be reversed: connected rings excited by an internal ac flux produce ballistic currents in the external wires. In particular we point out that, by employing suitable flux protocols, single-parameter nonadiabatic pumping can be achieved, and an arbitrary amount of charge can be transferred from one side to the other. We also propose a set up that could serve a memory device, in which both the operations of {\it writing} and {\it erasing} can be efficiently performed.
5 pages, 6 figures, accepted by Phys. Rev. B
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