Microscopic theory of vortex pinning on columnar defects in conventional and chiral superconductors
A. S. Mel'nikov+*, A. V. Samokhvalov+*, V. L. Vadimov+
+Institute for Physics of Microstructures of the RAS, 603950 Nizhny Novgorod, Russia
*Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
Abstract
The mechanisms of individual vortex pinning and stability of multivortex
configurations in different superconducting compounds and artificial
structures are analyzed on the basis of microscopic theory which allowed to
describe the corresponding modification of the anomalous spectral branches in
the quasiparticle spectrum caused by the electron scattering at the defect.
The individual pinning potentials and corresponding depinning currents are
evaluated. The experimentally observable consequences for the scanning
tunneling microscopy characteristics and high-frequency field response are
discussed. The comparative study of the conventional and chiral
superconductors allowed to suggest
experimental tests probing the superconducting gap symmetry. The chiral
superconductors are shown to reveal a strong dependence of the pinning
characteristics on the mutual orientation of the magnetic field and internal
angular momentum of the Cooper pair.