Magnetoresistance in Mn ion-implanted GaAs:Zn nanowires

Summary, in English

We have investigated the magnetoresistance (MR) in a series of Zn doped (p-type) GaAs nanowires implanted with different Mn concentrations. The nanowires with the lowest Mn concentration (similar to 0.0001%) exhibit a low resistance of a few k Omega at 300 K and a 4% positive MR at 1.6 K, which can be well described by invoking a spin-split subband model. In contrast, nanowires with the highest Mn concentration (4%) display a large resistance of several M Omega at 300 K and a large negative MR of 85% at 1.6 K. The large negative MR is interpreted in terms of spin-dependent hopping in a complex magnetic nanowire landscape of magnetic polarons, separated by intermediate regions of Mn impurity spins. Sweeping the magnetic field back and forth for the 4% sample reveals a hysteresis that indicates the presence of a weak ferromagnetic phase. We propose co-doping with Zn to be a promising way to reach the goal of realizing ferromagnetic Ga1-xMnxAs nanowires for future nanospintronics. (C) 2014 AIP Publishing LLC.

• Författare: Waldomiro Paschoal; Sandeep Kumar; Daniel Jacobsson; A. Johannes; Vishal Jain; C. M. Canali; A. Pertsova; C. Ronning; Kimberly Dick Thelander; Lars Samuelson; Håkan Pettersson
• Avdelning/ar: Fasta tillståndets fysik; Centrum för analys och syntes; NanoLund: Centre for Nanoscience
• Publiceringsår: 2014
• Språk: Engelska
• Publikation/Tidskrift/Serie: Applied Physics Letters
• Volym: 104
• Issue: 15
• Länkar: http://dx.doi.org/10.1063/1.4870423
• Dokumenttyp: Artikel i tidskrift
• Förlag: American Institute of Physics (AIP)
• Ämne: Chemical Sciences; Condensed Matter Physics
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 0003-6951