Room-temperature ferromagnetism and terahertz emission of Mn-doped InGaAs and GaAsSb nanowires.

Ferromagnetic Mn-doped In(0.05)Ga(0.95)As and GaAs(0.95)Sb(0.05) nanowires were synthesized by chemical vapor transport and their Mn concentration was about 2%. The Mn doped homogeneously into both the single-crystalline zinc blende InGaAs and GaAsSb without the formation of metal clusters. X-ray magnetic circular dichroism and magnetic moment measurements revealed their distinctive room-temperature ferromagnetic behaviors. While the incorporation of In enhances the ferromagnetism, that of Sb reduces it, which can be ascribed to the increase or decrease of the dopant-acceptor hybridization. These GaAs-based NWs exhibit an efficient terahertz emission at room temperature, due to a strong local field enhancement by coherent surface plasmons. The Mn doping significantly enhances the intensity and bandwidth of the terahertz emission, with an excellent correlation with their magnetization.