Conductance quantization at a half-integer plateau in a symmetric GaAs quantum wire.
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.
Crook
R
R
Cavendish Laboratory, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK. rc230@cam.ac.uk
Prance
J
J
Thomas
K J
KJ
Chorley
S J
SJ
Farrer
I
I
Ritchie
D A
DA
Pepper
M
M
Smith
C G
CG