Spontaneous spin polarisation in one dimension under finite DC-bias

Abstract We use the DC conductance of quantum wires to directly measure the energies of 1D states after they have populated; our results indicate that the 0.7 structure relates to the pinning in energy of the spin-up (higher energy) state. We also find evidence that the 0.85 ( 2 e 2 / h ) feature is partially spin-polarised even in zero magnetic field, and its differential conductance value is enhanced from 0.75 ( 2 e 2 / h ) by a subband dropping in energy with increasing V sd .