Perspective on the Vortex Mass Determination in Superconductors using Circular Dichroism

The effective mass of Abrikosov vortices in superconductors remains a challenging problem with limited experimental verification. In this paper, we present a method based on observation of the vortex mass in magnetic circular dichroism at terahertz frequencies. We demonstrate the emergence of dichroism with decreasing temperature in two YBa${}_2$Cu${}_3$O${}_{7-\delta }$ thin films of different doping. The experimental results can be explained within a theoretical model that takes into account the vortex mass and provides an expression for the optical complex conductivity. We discuss the model parameters and show how they are obtained from the supporting experiments.