title: Density-dependent spin polarization in ultra-low-disorder quantum wires.
abstract: There is controversy as to whether a one-dimensional (1D) electron gas can spin polarize in the absence of a magnetic field. Together with a simple model, we present conductance measurements on ultra-low-disorder quantum wires supportive of a spin polarization at B=0. A spin energy gap is indicated by the presence of a feature in the range (0.5-0.7)x2e(2)/h in conductance data. Importantly, it appears that the spin gap is not constant but a function of the electron density. Data obtained using a bias spectroscopy technique are consistent with the spin gap widening further as the Fermi level is increased.
authors.affiliation: Centre for Quantum Computer Technology, University of New South Wales, Sydney 2052, Australia. djr@jupiter.phys.unsw.edu.au
authors.forename: D J
authors.initials: DJ
authors.lastname: Reilly
authors.forename: T M
authors.initials: TM
authors.lastname: Buehler
authors.forename: J L
authors.initials: JL
authors.lastname: O'Brien
authors.forename: A R
authors.initials: AR
authors.lastname: Hamilton
authors.forename: A S
authors.initials: AS
authors.lastname: Dzurak
authors.forename: R G
authors.initials: RG
authors.lastname: Clark
authors.forename: B E
authors.initials: BE
authors.lastname: Kane
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West