Surface deformation and magnetocapacitance of superconductors

Electrostatic potentials have been measured at surfaces of superconductors in order to access directly the gap and material parameters. The reason why no thermodynamic corrections are measured as predicted by the theory, e.g. by Rickayzen, has remained a puzzle for almost 30 years. The solution is found in the Budd-Vannimenus theorem due to the surface dipoles. To access thermodynamic corrections one has to look deeper in the bulk like in an experiment by Kumagai et al measuring the quadrupole shift of the NMR in YBCO. The found large magnitude and unexpected sign is explained by the charge transfer between Cu chains and planes. To this end we develop the theory of electrostatic potentials above the Abrikosov vortex lattice within Bardeen's extension of the Ginzburg-Landau theory to low temperatures including the surface dipole.
As applications it is proposed:
(i) The deformation of the crystal due to the presence of vortices is calculated and the corresponding effective mass of vortices is suggested to be measured.
(ii) We found a jump of the magnetocapacitance at the surface critical magnetic field which should be experimentally accessible.

The experimentally confirmed Bernoulli potential is a consequence of the correla ted density which follows from the concept of nonlocal kinetic theory. Therefore we see this Bernoulli potential as a justification of our kinetic equation of nonlocal and non-instantaneous character which has unified the achievements of transport in dense gases with the quantum transport of dense Fermi systems.