Anomalous fractional conductance in one-dimensional quantum wires

Transport phenomena in one-dimensional (1D) quantum wires, particularly the quantization of conductance at fractional values of (e^2/h) without requiring a quantizing magnetic field, have garnered significant attention. When a weakly confined 1D channel is asymmetrically widened, we consistently observe several plateaus at fractional conductance values below the first plateau in high-quality electron systems formed in GaAs-based heterostructures.

In this study, we present recent experimental results that demonstrate the existence of both odd and even fractional quantum plateaus in the conductance of electrostatically defined 1D channels. These findings are analogous to those observed in the Fractional Quantum Hall Effect, despite the absence of a quantizing magnetic field. Furthermore, we highlight the significant impact of source-drain bias on these fractional states, particularly in the presence of in-plane magnetic fields.