Control of nuclear spins by quantum Hall edge channels

Abstract

Coherent control of local nuclear spins has been demonstrated based on a pulsed NMR in a quantum-Hall device. Compared to standard NMR measurements, the present work is distinguished by (39.1) its efficient initialization of nuclear-spin state via edge channels, (2) the local controllability of nuclear spins in a well-defined narrow region along the edge channels, and (3) the high sensitive electrical detection of nuclear polarization via conductance through the edge channels. Another potential strength of the present scheme may be its flexible device-design capability and the controllability. The location of polarized/detected nuclear spins is primarily defined by the incompressible region between spin-resolved edge channels. The location and the spatial pattern of edge channels can be manipulated during measurements with a simple gate biasing technique: The location of the incompressible strip can be controlled on nanometer-scale accuracy. Potentially, indirect interaction mediated by edge channels may serve as a means to control scalar coupling between different groups of nuclear spins. © 2006 Springer Science+Business Media, Inc.