Observation of a two-dimensional spin-lattice in non-magnetic semiconductor heterostructures
Abstract
Tunable magnetic interactions in high-mobility nonmagnetic semiconductor heterostructures are centrally important to spin-based quantum technologies. Conventionally, this requires incorporation of "magnetic impurities" within the two-dimensional (2D) electron layer of the heterostructures, which is achieved either by doping with ferromagnetic atoms, or by electrostatically printing artificial atoms or quantum dots. Here we report experimental evidence of a third, and intrinsic, source of localized spins in high-mobility GaAs/AlGaAs heterostructures, which are clearly observed in the limit of large setback distance (=80 nm) in modulation doping. Local nonequilibrium transport spectroscopy in these systems reveals existence of multiple spins, which are located in a quasi-regular manner in the 2D Fermi sea, and mutually interact at temperatures below 100 milliKelvin via the Ruderman-Kittel-Kasuya-Yosida (RKKY) indirect exchange. The presence of such a spin-array, whose microscopic origin appears to be disorder-bound, simulates a 2D lattice-Kondo system with gate-tunable energy scales.
Keywords
Cite
@article{arxiv.cond-mat/0701519,
title = {Observation of a two-dimensional spin-lattice in non-magnetic semiconductor heterostructures},
author = {Christoph Siegert and Arindam Ghosh and Michael Pepper and Ian Farrer and David A. Ritchie},
journal= {arXiv preprint arXiv:cond-mat/0701519},
year = {2007}
}
Comments
7 pages + 4 figs. To appear in Nature Physics. This is the original submitted version. Final version will be posted six months after publication. The Supplementary Information can be downloaded from: http://www.physics.iisc.ernet.in/~arindam/Supplementary_Information_NPHYS-2006-08-0 0812B.pdf