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Electrical Generation of Pure Spin Currents in a Two-Dimensional Electron Gas

2009; American Physical Society; Volume: 102; Issue: 11 Linguagem: Inglês

10.1103/physrevlett.102.116802

1092-0145

Sergey Frolov, A. Venkatesan, Wing Wa Yu, Joshua Folk, W. Wegscheider,

Semiconductor Quantum Structures and Devices

Pure spin currents are generated and detected in micron-wide channels of a GaAs two-dimensional electron gas, using quantum point contacts in an in-plane magnetic field as injectors and detectors. The enhanced sensitivity to spin transport offered by a nonlocal measurement geometry enables accurate spin current measurements in this widely studied physical system. The polarization of the contacts is used to extract the quantum point contact g factor and provides a test for spontaneous polarization at 0.7 structure. The spin relaxation length in the channel is 30-50 microm over the magnetic field range 3-10 T, much longer than has been reported in GaAs two-dimensional electron gases but shorter than that expected from Dyakonov-Perel relaxation.