Gate induced quantum wires in GaAs/AlGaAs heterostructures by cleaved edge deposition

For CEO samples the lateral confinement is created by the doped overgrowth of the cleaved edge. In contrast to that for the CED samples the confinement is induced by applying a positive side-gate voltage. Figure 2 shows the effect of different side-gate voltages on the conductance plateaus of a CED sample. The quantization steps in the plot start to form with increasing positive side-gate voltage, getting broader and more pronounced. Remarkably, almost no deviation of the conductance (G) from the universal conductance quantization (G0) can be seen down to temperatures of 25 mK. This is in contrast to most other CEO samples studied, where the deviation is present but the origin is not clear and different explanations are given8.

Figure 2

Dependence of conductance on the top-gate (TG)…

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