Singlet-Triplet Superconducting Quantum Magnetometer

TL;DR

This paper demonstrates that incorporating textured ferromagnets in superconducting quantum magnetometers enhances flux sensitivity and enables singlet-triplet switching, leveraging spin-triplet correlations for improved device functionality.

Contribution

It introduces a method to utilize spin-triplet correlations in superconducting devices to significantly enhance magnetometer sensitivity and control.

Findings

Enhanced flux sensitivity with textured ferromagnets.

Ability to switch between singlet and triplet states via bias voltage.

Potential for improved ultra-sensitive magnetic sensors.

Abstract

Motivated by the recent experimental realization of a quantum interference transistor based on the superconducting proximity effect, we here demonstrate that the inclusion of a textured ferromagnet both strongly enhances the flux sensitivity of such a device and additionally allows for singlet-triplet switching by tuning a bias voltage. This functionality makes explicit use of the induced spin-triplet correlations due to the magnetic texture. Whereas the existence of such triplet correlations is well-known, our finding demonstrates how spin-triplet superconductivity may be utilized for concrete technology, namely to improve the functionality of ultra-sensitive magnetometers.