Utilising the Aharonov-Bohm effect in quantum device design

The Aharonov-Bohm effect – where electron-interference fringe positions are shifted based on the presence of a non-local magnetic field – has not yet been utilised to its full potential in quantum device design. In this paper, we show that the de Broglie wavelength of the electron is changed locally by its interaction with the magnetic vector potential. The vector potential thus acts as a quantum “phase plate”, changing the phase difference between interfering electron wavefunctions in a non-dispersive, gauge-invariant manner. This model is then shown to be applicable to the design and optimisation of phase-dependent quantum devices such as superconducting quantum interference devices (SQUIDs), quantum sensors, and so on.