Electrical generation of pure spin currents in a two-dimensional electron gas.
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.
Frolov
S M
SM
Department of Physics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Venkatesan
A
A
Yu
W
W
Folk
J A
JA
Wegscheider
W
W