Magnetic Polarons and Large Negative Magnetoresistance in GaAs Nanowires Implanted with Mn Ions.

Summary, in English

We report on low-temperature magnetotransport and SQUID measurements on heavily doped Mn-implanted GaAs nanowires. SQUID data recorded at low magnetic fields exhibit clear signs of the onset of a spin-glass phase with a transition temperature of about 16 K. Magnetotransport experiments reveal a corresponding peak in resistance at 16 K and a large negative magnetoresistance, reaching 40% at 1.6 K and 8 T. The negative magnetoresistance decreases at elevated temperatures and vanishes at about 100 K. We interpret our transport data in terms of spin-dependent hopping in a complex magnetic nanowire landscape of magnetic polarons, separated by intermediate regions of Mn impurity spins, forming a paramagnetic/spin-glass phase.

• Författare: Sandeep Kumar; Waldomiro Paschoal; Andreas Johannes; Daniel Jacobsson; Christian Borschel; Anna Pertsova; Chih-Han Wang; Maw-Kuen Wu; Carlo M Canali; Carsten Ronning; Lars Samuelson; Håkan Pettersson
• Avdelning/ar: Fasta tillståndets fysik; NanoLund: Centre for Nanoscience
• Publiceringsår: 2013
• Språk: Engelska
• Sidor: 5079-5084
• Publikation/Tidskrift/Serie: Nano Letters
• Volym: 13
• Issue: 11
• Länkar: http://dx.doi.org/10.1021/nl402229r
• Dokumenttyp: Artikel i tidskrift
• Förlag: The American Chemical Society (ACS)
• Ämne: Nano Technology
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1530-6992