Thermodynamics of a single manipulable superconducting vortex

A superconducting vortex is a persistent current forming a loop trapping a quantized amount of the magnetic flux in the superconductor. Vortices, observed in 2nd-type superconductivity, can move in superconducting devices and become a source of dissipation.

The studies that aim at the complete description of vortex systems are hindered by two issues. Usually, many vortices are present in the sample at the same time. This fact enables the interaction between them and makes it difficult to study their individual dynamics. Researchers have been able to see vortex lattices, but they have not been able to control on demand their detailed behavior. Additionally, the dissipation associated with the vortex movement is so fast that no research method to date has been able to investigate it. In principle, such dissipation should leave a measurable dynamical thermal footprint, but no temperature measuring methods have been sufficiently fast to trace it. Our pioneering approach to study vortices allows us to overcome these two limitations and shine a new light on the physics of a single moving vortex.

I will show our recent achievement of monitoring, but more importantly fully controlling of a single superconducting vortex [1]. We trap vortex in the aluminum nanosquare [2], and using the fast switching thermometry developed in our lab over recent years, we are able to measure its thermal dynamics [3, 4]. We take advantage of the functionality of a superconducting vortex trap and a superconducting thermometer. It allows for the direct measurement of temperature dynamics due to the current-induced expulsion of a vortex from the superconductor. We measure the stability of a single vortex with various magnetic fields, and we extract the energy dissipated in an expulsion event. The determined energy is in the range of a single electronovolt, and the thermal dynamics that follows the expulsion process last several hundreds of nanoseconds. Our studies lay the foundations for a new field of vortex electronics, in which we treat a vortex as an information carrier instead of an electron.

[1] Foltyn et al., Science Advances 10, eado4032 (2024)
[2] Foltyn et al., Phys. Rev. Applied 19, 044073 (2023)
[3] Zgirski et al., Phys. Rev. Applied 14, 044024 (2020)
[4] Zgirski et al., Phys. Rev. Applied 10, 044068 (2018)