2D‐patterned ferromagnetic III‐Mn‐V semiconductors for planar spintronics

Abstract

We demonstrate planar patterning techniques to produce isolated regions of ferromagnetic Ga1–xMnxAs embedded in a GaAs host. One technique consists of ion-implantation through lithographically defined resist, followed by pulsed-laser melting. Planar Hall-bar structures of Ga1–xMnxAs formed by this process show a large anomalous Hall signal along with negative magnetoresistance associated with the well-known hole-mediated ferromagnetic phase. In another technique patterning is achieved by selective hydrogenation of Ga1–xMnxAs, rendering exposed regions electrically insulating and magnetically inactive. The planar nature of these Hall-bars allows for tuning the ferromagnetism by the integration of lateral gates to modulate the exchange-mediating hole population in the Ga1–xMnxAs region, hence creating junction-FET functionality. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)