Parity Fluctuations Between Coulomb Blockaded Superconducting Islands

TL;DR

This paper investigates parity fluctuations between Coulomb blockaded superconducting islands connected by a tunnel junction, revealing a novel temperature-dependent telegraph noise phenomenon observable in single-electron devices.

Contribution

It introduces the concept of parity fluctuation-induced telegraph noise in coupled superconducting islands, highlighting a new physical effect not previously characterized.

Findings

Unpaired electron tunneling causes parity fluctuations.

The noise spectrum exhibits an unusual temperature dependence.

The phenomenon is observable in Cooper-pair pumps and similar devices.

Abstract

We find that if two superconducting islands of different number parity are linked by a tunnel junction the unpaired electron in the odd island has a tendency to tunnel into the even island. This process leads to fluctuations in time of the number parity of each island, giving rise to a random telegraph noise spectrum with a characteristic frequency that has an unusual temperature dependence. This new phenomenon should be observable in a Cooper-pair pump and similar single-electron tunneling devices.