Finite-size effects in tunneling between parallel quantum wires

TL;DR

This paper combines theoretical and experimental approaches to study finite-size effects in tunneling between parallel quantum wires, revealing oscillations and excitations related to the confining potential and spin-charge separation.

Contribution

It provides new insights into finite-size effects and excitation velocities in quantum wire tunneling through combined calculations and measurements.

Findings

Oscillations in differential conductance linked to confining potential shape

Detection of two distinct excitation velocities

Evidence of spin-charge separation in tunneling behavior

Abstract

We present theoretical calculations and experimental measurements which reveal finite-size effects in the tunneling between two parallel quantum wires, fabricated at the cleaved edge of a GaAs/AlGaAs bilayer heterostructure. Observed oscillations in the differential conductance, as a function of bias voltage and applied magnetic field, provide direct information on the shape of the confining potential. Superimposed modulations indicate the existence of two distinct excitation velocities, as expected from spin-charge separation.