title: Conductance quantization at a half-integer plateau in a symmetric GaAs quantum wire.
abstract: We present data from an induced gallium arsenide (GaAs) quantum wire that exhibits an additional conductance plateau at 0.5(2e2/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.
authors.affiliation: Cavendish Laboratory, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK. rc230@cam.ac.uk
authors.forename: R
authors.initials: R
authors.lastname: Crook
authors.forename: J
authors.initials: J
authors.lastname: Prance
authors.forename: K J
authors.initials: KJ
authors.lastname: Thomas
authors.forename: S J
authors.initials: SJ
authors.lastname: Chorley
authors.forename: I
authors.initials: I
authors.lastname: Farrer
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie
authors.forename: M
authors.initials: M
authors.lastname: Pepper
authors.forename: C G
authors.initials: CG
authors.lastname: Smith