Vortices in Superfluids and Superconductors

William Frank Vinen

Григорий Ефимович Воловик

The bound states of fermions in cores of quantized vortices in superconductors and Fermi superfluids and their influence on the vortex dynamics are discussed. The role of the spectral flow of the fermions through the gap nodes is emphasized.

Qiang Du

Abstract Quantized vortices is a well‐know signature of superfluidity. They have been studied extensively in superfluid Helium, type‐II superconductors, Bose Einstein condensates and more recently in Fermi gas. We will discuss some mathematical analysis and numerical simulations of the quantized vortex nucleations in superconductors and Bose‐Einstein condensates and discuss their connections and similarities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Lucy J. Campbell

Jonathan Schirmer, Enrico Rossi

In this work, we obtain the superfluid weight of strongly inhomogeneous superconductors. We find that, in general, the response of the superconductor's pairing potential to the perturbing vector potential is essential to obtain the correct value of the superfluid weight. We consider two exemplary cases: the case when strong inhomogeneities in the pairing potential are induced by a periodic potential, and the case when superconducting vortices are induced by an external magnetic field. For both cases we show that the correction to the superfluid weight due to the response of the paring potential to the perturbing vector potential can be significant, it must be included to obtain quantitatively correct results, and that for the case when vortices are present the expression of the superfluid weight that does not include such correction returns qualitatively wrong results. The results are directly relevant for superconducting states in moir\'e multilayer where the almost inevitable spatial variations of the magic angle and the proximity of superconductivity to anisotropic phases induce inhomogeneities in the pairing potential, and to the efforts to optimally pin superconducting vortices to achieve large superconducting critical currents.