Measuring geometric phases of scattering states in nanoscale electronic devices

TL;DR

This paper introduces a method to measure the geometric phase of scattering states in nanoscale electronic devices using interference in a double path interferometer, revealing new quantum properties.

Contribution

It proposes an experimental setup to directly observe geometric phases in scattering states, extending quantum phase measurement techniques to nanoscale electronic systems.

Findings

Interference oscillations reveal geometric phases in nanoscale devices.

Both Abelian and non-Abelian gauge potentials induce observable effects.

The method enables direct measurement of geometric phases in quantum transport.

Abstract

We show how a new quantum property, a geometric phase, associated with scattering states can be exhibited in nanoscale electronic devices. We propose an experiment to use interference to directly measure the effect of the new geometric phase. The setup involves a double path interferometer, adapted from that used to measure the phase evolution of electrons as they traverse a quantum dot (QD). Gate voltages on the QD could be varied cyclically and adiabatically, in a manner similar to that used to observe quantum adiabatic charge pumping. The interference due to the geometric phase results in oscillations in the current collected in the drain when a small bias across the device is applied. We illustrate the effect with examples of geometric phases resulting from both Abelian and non-Abelian gauge potentials.