title: A new route toward semiconductor nanospintronics: highly Mn-doped GaAs nanowires realized by ion-implantation under dynamic annealing conditions.
abstract: We report on highly Mn-doped GaAs nanowires (NWs) of high crystalline quality fabricated by ion beam implantation, a technique that allows doping concentrations beyond the equilibrium solubility limit. We studied two approaches for the preparation of Mn-doped GaAs NWs: First, ion implantation at room temperature with subsequent annealing resulted in polycrystalline NWs and phase segregation of MnAs and GaAs. The second approach was ion implantation at elevated temperatures. In this case, the single-crystallinity of the GaAs NWs was maintained, and crystalline, highly Mn-doped GaAs NWs were obtained. The electrical resistance of such NWs dropped with increasing temperature (activation energy about 70 meV). Corresponding magnetoresistance measurements showed a decrease at low temperatures, indicating paramagnetism. Our findings suggest possibilities for future applications where dense arrays of GaMnAs nanowires may be used as a new kind of magnetic material system.
authors.affiliation: Institute for Solid State Physics, Jena University, Max-Wien-Platz 1, 07743 Jena, Germany. christian.borschel@uni-jena.de
authors.forename: Christian
authors.initials: C
authors.lastname: Borschel
authors.forename: Maria E
authors.initials: ME
authors.lastname: Messing
authors.forename: Magnus T
authors.initials: MT
authors.lastname: Borgström
authors.forename: Waldomiro
authors.initials: W
authors.lastname: Paschoal
authors.forename: Jesper
authors.initials: J
authors.lastname: Wallentin
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.forename: Kilian
authors.initials: K
authors.lastname: Mergenthaler
authors.forename: Knut
authors.initials: K
authors.lastname: Deppert
authors.forename: Carlo M
authors.initials: CM
authors.lastname: Canali
authors.forename: Håkan
authors.initials: H
authors.lastname: Pettersson
authors.forename: Lars
authors.initials: L
authors.lastname: Samuelson
authors.forename: Carsten
authors.initials: C
authors.lastname: Ronning