0.7 Structure in quantum wires observed at crossings of spin-polarised 1D subbands

Low-density ballistic 1D wires defined in GaAs/AlGaAs heterostructures show a spontaneous spin-splitting at crossings of Zeeman-split levels induced by an in-plane magnetic field, giving rise to additional unexpected conductance features. From measurements of magnetic field and temperature dependences, we suggest that the mechanism associated with the new features is similar to that of the 0.7 structure observed at zero magnetic field.