Conductance Quantization at a Half-Integer Plateau in a Symmetric GaAs Quantum Wire
R. Crook,*
J. Prance,
K. J. Thomas,
S. J. Chorley,
I. Farrer,
D. A. Ritchie,
M. Pepper,
C. G. Smith
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.
Cavendish Laboratory, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK.
* To whom correspondence should be addressed. E-mail: rc230{at}cam.ac.uk
