Hydrogen patterning of Ga1-xMnxAs for planar spintronics

TL;DR

This paper introduces hydrogen passivation patterning techniques for Ga1-xMnxAs, enabling the creation of isolated ferromagnetic regions with high spatial resolution for advanced spintronic applications.

Contribution

It presents two novel hydrogenation patterning methods for Ga1-xMnxAs, achieving high-resolution ferromagnetic region isolation and local reactivation for spintronics.

Findings

Arrays of 250 nm Ga1-xMnxAs dots demonstrated

Local electrical reactivation of micrometer regions shown

Potential for <100 nm resolution with near-field laser processing

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.