Quantum effects in linear and non-linear transport of T-shaped ballistic junction

TL;DR

This study investigates quantum effects in a T-shaped ballistic junction, revealing mode branching, bend resistance, wave function parity influence, and voltage behavior in non-linear regimes at low temperatures.

Contribution

It provides experimental evidence of quantum transport phenomena and non-linear effects in T-shaped ballistic junctions, supported by numerical modeling.

Findings

Mode branching and bend resistance observed

Backscattering depends on wave function parity

Floating electrode voltage increases with push-pull polarization

Abstract

We report low-temperature transport measurements of three-terminal T-shaped device patterned from GaAs/AlGaAs heterostructure. We demonstrate the mode branching and bend resistance effects predicted by numerical modeling for linear conductance data. We show also that the backscattering at the junction area depends on the wave function parity. We find evidence that in a non-linear transport regime the voltage of floating electrode always increases as a function of push-pull polarization. Such anomalous effect occurs for the symmetric device, provided the applied voltage is less than the Fermi energy in equilibrium.