Vortex rectification effects in plain superconducting films

TL;DR

This paper demonstrates that plain superconducting films can rectify alternating currents due to vortex dynamics, without the need for asymmetric pinning sites, with effects depending on magnetic field and current frequency.

Contribution

It reveals vortex rectification in plain superconducting films at high frequencies, challenging previous assumptions about the necessity of asymmetric pinning sites.

Findings

Rectification occurs in plain superconducting films without engineered pinning sites.

The rectified voltage depends on magnetic field and current frequency.

Vortex motion underpins the rectification effect.

Abstract

Superconducting films in perpendicular magnetic field are found to rectify alternating currents. The effect has been observed both in plain and nanostructured superconducting films (niobium and lead). The rectified voltage appears both along and transverse to alternating current and strongly depends on the magnetic field. Rectification phenomena is based on the property of superconductors to have permanent circulating currents in magnetic field (vortices) and to develop electric fields at high enough currents. In contrast to previous findings, at higher current frequencies no asymmetric pinning sites are needed to produce rectification and related guided flux motion.