The 0.7 structure in Cleaved Edge Overgrowth Wires

We study the temperature dependence of the conductance in clean one-dimensional wires fabricated by cleaved edge overgrowth in molecular beam epitaxy. At elevated temperatures, a conductance peculiarity occurs at low electron densities. The linear conductance dwells at a value of ~70% of it's plateau value over a finite density range. We show that this, so-called "0.7 structure", arises as the electrons in the wire undergo a transition from a degenerate into a non-degenerate liquid.