NER: Acoustic Spintronics for Applications in Quantum Optics and Computing

Cuny Hunter College, New York NY

Investigators

Abstract

This award for Nanoscale Exploratory Research (NER) is a result of a proposal submitted to the Nanoscale Science and Engineering initiative. The award is funded jointly Divisions of Materials Research and Computer Communications Research. Working closely with experimental groups, this theoretical research will study novel acoustic nanocircuits in which semiconductor quasi-one-dimensional channels serve as wires through which powerful surface acoustic waves transport single electrons along the channels. The possibility of controlling the electron spin in such circuits is explored. This "acoustic spintronics" may find applications in quantum optics and quantum computing. The nanocircuits comprise a network of semiconductor channels along which charge is transported by a sliding, partially modulated, electrostatic potential created with the help of a surface acoustic wave. The charge is transported in the form of the submicron-sized packets (residing in the minima of the moving potential) so that the packets can be thought of as moving quantum dots. The regime of operation when each moving dot carries just one electron will be thoroughly investigated. Viability of this regime stems from recent experiments of the single electron transport by surface acoustic waves in a one-dimensional GaAs-AlGaAs semiconductor channel. The main objective of this research is to analyze one specific nanocircuit that comprises all the basic elements necessary for control, entanglement and measurement of the electron spin states in the moving dots. The circuit should be applicable to quantum computation with a qubit encoded by the electron spin. The proposed scheme has important advantages as compared with other proposals employing semiconductor quantum dots because the ability to move dots around a circuit offers simple technical solutions for single-, two-qubit, and read-out operations. The proposed nanocircuit includes an optoelectronic component in which transport of single electrons from n- to p-type two-dimensional conductive areas takes place. In the p-region the electrons recombine with the holes thus emitting photons. Single photon sources and sources of entangled photon pairs with a well-defined generation time can be realized within the suggested scheme. %%% This award for Nanoscale Exploratory Research (NER) is a result of a proposal submitted to the Nanoscale Science and Engineering initiative. The award is funded jointly Divisions of Materials Research and Computer Communications Research. Working closely with experimental groups, this theoretical research will study novel acoustic nanocircuits in which semiconductor quasi-one-dimensional channels serve as wires through which powerful surface acoustic waves transport single electrons along the channels. The possibility of controlling the electron spin in such circuits is explored. This "acoustic spintronics" may find applications in quantum optics and quantum computing. ***