SELF-TRAPPING OF ELECTRONS BY VORTICES

It is shown that electrons associated with vortices may be self-trappe d by lattice deformations. In essence, the deformation creates a well in which part of the electrons associated with vortex cores are trappe d. The effect is strongest in superconductors which have a strong elec tron-phonon coupling, a large coherence length and a significant ratio Delta/epsilon(F). The associated lattice deformations have been obser ved in a spin-polarised neutron scattering experiment on superconducti ng Nb.