Superconductivity, diamagnetism, and the mean inner potential of solids

Abstract

The mean inner potential of a solid is known to be proportional to its diamagnetic susceptibility. Superconductors exhibit giant diamagnetism. What does this say about the connection between superconductivity and mean inner potential? Nothing, according to the conventional theory of superconductivity. Instead, we propose that a deep connection exists between the mean inner potential, diamagnetism, and superconductivity: that they are all intimately linked to the fundamental charge asymmetry of matter. We discuss how this physics can be probed experimentally and what the implications of different experimental findings would be for the understanding of superconductivity.Comment: Small changes in response to referee's comments. To be published in Annalen der Physi

Moment of inertia of superconductors

“…Shortly thereafter, Rosenfeld [29] pointed out that the mean inner potential is proportional to the diamagnetic susceptibility. In other work we have pointed out [30] that the same physics discussed here, increase in electronic moment of inertia when a normal metal becomes superconducting, should lead to an increase in both its diamagnetic susceptibility (as observed) and in its mean inner potential, which can be measured by electron holography [31] (not yet observed).…”

“…Because Eq. (30) no longer depends on the geometry of the body we believe it is very likely that it is a general result for a body of arbitrary shape and for any rotation axis. Note the interesting fact that Eq.…”

Dynamic Hubbard model: kinetic energy driven charge expulsion, charge inhomogeneity, hole superconductivity and Meissner effect

“…The charge expulsion predicted by the electrodynamic equations is of the order of 1 extra electron every 10 6 sites near the surface [71], which certainly would not be noticeable in systems of the size considered here. We have recently proposed that this predicted macroscopic charge inhomogeneity in the superconducting state should be experimentally observable through the technique of electron holography [72][73][74][75].…”

“…These electric fields should be experimentally detectable in the neighborhood of superconductors at temperature lower than T cr . In addition, the internal electric field should be directly detectable in electron holography experiments [72][73][74]. The magnitude of these predicted electric fields is of order of H c1 , the lower critical magnetic field, in the interior of the superconductor [71], and an appreciable fraction of it in the region outside the superconductor near the surface, depending on the shape of the body [67,68].…”

Direct Measurement of the Electrical Abruptness of a Nanowire p–n Junction

“…Under the assumption that there is negligible loss of beam intensity via dynamical diffraction while passing through the sample (kinematical assumption), the electron’s net phase change along the microscope z -axis, relative to the vacuum reference at 0 rads, is where z i is the displacement of the i th unit element along the beam axis from the NW center with projected unit path length Δ z i , and x and r are the axial and radial coordinates, respectively. Here, C E is an electron-energy-dependent interaction constant (7.30 × 10 –3 rad V –1 nm –1 at 200 keV), and V is the sum of the mean inner potential V MIP (14.1 V for GaAs and 9.1 V for carbon, a characteristic parameter of the material, and the built-in electric potentials δ V ( x , r , z i ) within the NW.…”