Electronic Transport in a Quasi-Ballistic Narrow Wire Confined by Split Metal Gates
A quasi-ballistic narrow channel was confined in a 2 dimensional electron gas (2DEG) formed at the heterointerface between GaAs and AlGaAs in terms of split metallic gates defined by electron beam lithography. Magnetoresistance (MR) measurements were made at 1.2 K and under a magnetic field of up to 8 T. Shubnikov-de Haas (SdH) oscillations and conductance fluctuations were observed. The effect of side wall scatterings on the relaxation process and the width dependence of conductance fluctuations were studied. It was found that (1) in high magnetic fields where edge states begin to be important, scattering with side walls was a dominant relaxation mechanism, and (2) the amplitude of conductance fluctuations began to decrease from a constant value with decreasing width. The observed effects were specific to the quasi-ballistic transport regime.
KeywordsGate Voltage High Magnetic Field Edge State Electron Beam Lithography Transport Regime
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