Conductance quantization at a half-integer plateau in a symmetric GaAs quantum wire

Crook, R. and Prance, J. and Thomas, K. J. and Chorley, S. J. and Farrer, I. and Ritchie, D. A. and Pepper, M. and Smith, C. G. (2006) Conductance quantization at a half-integer plateau in a symmetric GaAs quantum wire. Science, 312 (5778). pp. 1359-1362. ISSN 0036-8075

Abstract

We present data from an induced gallium arsenide ( GaAs) quantum wire that exhibits an additional conductance plateau at 0.5(2e(2)/h), where e is the charge of an electron and h is Planck's constant, in zero magnetic field. The plateau was most pronounced when the potential landscape was tuned to be symmetric by using low-temperature scanning-probe techniques. Source-drain energy spectroscopy and temperature response support the hypothesis that the origin of the plateau is the spontaneous spin-polarization of the transport electrons: a ferromagnetic phase. Such devices may have applications in the field of spintronics to either generate or detect a spin-polarized current without the complications associated with external magnetic fields or magnetic materials.