Phase coherent transport in GaAs/AlGaAs core–shellnanowires

We report on low temperature magneto-conductance measurements of a single modulation-doped GaAs/AlGaAs core–shell nanowire in transverse magnetic field. Information on the phase coherence length l ϕ is obtained from quantum conductivity corrections due to weak localization effects or universal conductance fluctuation. The nanowires are totally coherent at very low temperature and l ϕ could be larger than 250 nm at 4 K. The temperature dependence of l ϕ shows that the main dephasing mechanism is the one-dimensional electron–electron scattering mechanism.