Vortex Ring and Helical Current Formation in Superconductors Driven by a THz-Field-Induced Toroidal Vector Potential

Abstract

Herein, the vortex dynamics in a type II superconducting torus driven by a curl-free vector potential corresponding to a toroidal moment is studied, which is triggered within picoseconds in an enclosed semiconductor by polarization-structured THz vector field pulses. Numerical simulations of the time-dependent Ginzburg–Landau equation in the presence of the toroidal vector potential evidence the formation of vortex ring structures that depend on the toroidal moment strength with a behavior resembling the Little–Parks effect. Applying in addition a static external magnetic flux density, the induced textures in the superconducting phase can be stabilized and steered to form stripe domains with corresponding helical supercurrent density.