Spin Polarization in a AlGaAs/GaAs Quantum Point Contact with in-plane   side gates
  We report the observation of an anomalous conductance plateau near G = 0.5 G0 (G0 = 2e2/h) in asymmetrically biased AlGaAs/GaAs quantum point contacts (QPCs), with in-plane side gates in the presence of lateral spin-orbit coupling. This is a signature of spin polarization in the narrow portion of the QPC. The appearance and evolution of the conductance anomaly has been studied at T=4.2K as a function of the potential asymmetry between the side gates. The observation of spontaneous spin polarization in a side-gated GaAs QPC could eventually lead to the realization of an all-electric spin-valve at tens of degrees Kelvin. 
N. Bhandari, P. P. Das, M. Cahay, R. S. Newrock, and S. T. Herbert
cond-mat.mes-hall