Electromagnetic Effects in Superconductors in Gravitational Field

TL;DR

This paper investigates how gravitational fields influence superconductors, predicting measurable effects such as frequency shifts and magnetic flux generation due to general relativistic phenomena like frame dragging.

Contribution

It introduces theoretical predictions of gravitational effects on superconducting properties, including frequency shifts and magnetic flux induced by relativistic frame dragging.

Findings

Gravity affects AC Josephson frequency in superconductors.

Rotating superconductors can generate magnetic flux due to relativistic effects.

Magnetic flux in neutron stars is influenced by frame dragging and thermoelectric currents.

Abstract

The general relativistic modifications to the resistive state in superconductors of second type in the presence of a stationary gravitational field are studied. Some superconducting devices that can measure the gravitational field by its red-shift effect on the frequency of radiation are suggested. It has been shown that by varying the orientation of a superconductor with respect to the earth gravitational field, a corresponding varying contribution to AC Josephson frequency would be added by gravity. A magnetic flux (being proportional to angular velocity of rotation $\Omega$) through a rotating hollow superconducting cylinder with the radial gradient of temperature $\nabla_r T$ is theoretically predicted. The magnetic flux is assumed to be produced by the azimuthal current arising from Coriolis force effect on radial thermoelectric current. Finally the magnetic flux through the superconducting ring with radial heat flow located at the equatorial plane interior the rotating neutron star is calculated. In particular it has been shown that nonvanishing magnetic flux will be generated due to the general relativistic effect of dragging of inertial frames on the thermoelectric current.