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arXiv · 0708.0389

Hydrogen patterning of Ga1-xMnxAs for planar spintronics

R. Farshchi·P. D. Ashby·D. J. Hwang·C. P. Grigoropoulos·R. V. Chopdekar·Y. Suzuki·O. D. Dubon
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Abstract

We demonstrate two patterning techniques based on hydrogen passivation of Ga1-xMnxAs to produce isolated ferromagnetically active regions embedded uniformly in a paramagnetic, insulating host. The first method consists of selective hydrogenation of Ga1-xMnxAs by lithographic masking. Magnetotransport measurements of Hall-bars made in this manner display the characteristic properties of the hole-mediated ferromagnetic phase, which result from good pattern isolation. Arrays of Ga1-xMnxAs dots as small as 250 nm across have been realized by this process. The second process consists of blanket hydrogenation of Ga1-xMnxAs followed by local reactivation using confined low-power pulsed-laser annealing. Conductance imaging reveals local electrical reactivation of micrometer-sized regions that accompanies the restoration of ferromagnetism. The spatial resolution achievable with this method can potentially reach <100 nm by employing near-field laser processing. The high spatial resolution attainable by hydrogenation patterning enables the development of systems with novel functionalities such as lateral spin-injection as well as the exploration of magnetization dynamics in individual and coupled structures made from this novel class of semiconductors.

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R. Farshchi, P. D. Ashby, D. J. Hwang, C. P. Grigoropoulos, R. V. Chopdekar, Y. Suzuki, O. D. Dubon. 2007-08-02. Hydrogen patterning of Ga1-xMnxAs for planar spintronics. https://doi.org/10.1016/j.physb.2007.08.208

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