Hall effect over integral filling factors in GaAs/AlxGa1-xAs quantum wires.

Abstract

Two-terminal resistance (R) measurements are used to investigate the low-temperature (T1.4 K) Hall effect in GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As quantum wires with a geometrical width smaller than 400 nm, in order to eliminate the possible invasive influence of (Hall) voltage leads in standard four-terminal (Hall-bar-type) configurations. Experiment shows that although R assumes a temperature- and length-independent value near integral filling factors, i.e., ${\mathit{R}}_{\mathit{x}\mathit{x}}$\ensuremath{\rightarrow}0, the remaining Hall resistance R=${\mathit{R}}_{\mathit{x}\mathit{y}}$ exhibits a finite slope vs B unlike two-dimensional systems. The results suggest that long disordered electronic wires can exhibit an ordinary Hall effect in the vicinity of integral filling factors.