Large spin accumulation and crystallographic dependence of spin transport in single crystal gallium nitride nanowires

Semiconductor spintronics is an alternative to conventional electronics that offers devices with high performance, low power and multiple functionality. Although a large number of devices with mesoscopic dimensions have been successfully demonstrated at low temperatures for decades, room-temperature operation still needs to go further. Here we study spin injection in single-crystal gallium nitride nanowires and report robust spin accumulation at room temperature with enhanced spin injection polarization of 9%. A large Overhauser coupling between the electron spin accumulation and the lattice nuclei is observed. Finally, our single-crystal gallium nitride samples have a trigonal cross-section defined by the (001), (11 (2) over bar) and ((1) over bar(1) over bar(2) over bar) planes. Using the Hanle effect, we show that the spin accumulation is significantly different for injection across the (001) and ((1) over bar(1) over bar(2) over bar) (or (11 (2) over bar)) planes. This provides a technique for increasing room temperature spin injection in mesoscopic systems.