Quantum conductivity corrections in free-standing and supported n⁺-GaAs wires

Low-temperature electrical and magnetoresistance measurements have been performed on free-standing and supported wires of n-type GaAs doped to 10 17 cm -3 over the temperature range 0.47-4.2 K. These wires were triangular in cross-section, with widths of 600-900 nm and lengths of 3.2-10 mu m. The authors report that the observed increase in the resistance for temperatures below 4.2 K can be interpreted as being due to a combination of weak localisation of 3D electron-electron interaction effects. They also show how the results described here can be used as the basis for a determination of the phonon conductivity and dimensionality in free-standing structures.