Localization at high magnetic fields in GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As quantum wires

A low-temperature (0.03<T<1.9 K) magnetotransport study of GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As wires with a geometrical width e${\mathit{d}}^{\mathit{t}\mathit{w}\mathit{o}\mathrm{-}\mathit{d}\mathit{i}\mathit{m}\mathit{e}\mathit{n}\mathit{s}\mathit{i}\mathit{o}\mathit{n}\mathit{a}\mathit{l}}$ (2D)GaAs/Al${\mathrm{\$}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As. The data suggest that T-induced electronic localization, which is characterized by a power-law variation in the half-width at half-maximum of the SdH linewidth (ΔB∼${\mathit{T}}^{0.4}$), occurs only on the low-energy side of the 1D Landau bands, while the high-energy side remains relatively unaffected, in sharp contrast to the 2D behavior. These results show that the transport properties of wires do not assume standard 2D characteristics even when ${\mathit{L}}_{\mathit{B}}$=(ħ/eB${)}^{1/2}$<W.