Screening of magnetic fields by charged Bose condensate

TL;DR

This paper investigates how magnetic fields are screened in a medium with a charged Bose-Einstein condensate, revealing a novel magnetic screening effect similar to superconductivity but with unique oscillatory behavior at finite temperatures.

Contribution

It introduces the calculation of the photon polarization operator in a charged BEC medium, uncovering a new magnetic screening phenomenon not observed in conventional superconductors.

Findings

Magnetic fields are exponentially screened in charged BEC media.

At finite temperature, the screened magnetic field exhibits oscillations.

A contribution to magnetic field decay drops as a power of distance.

Abstract

The space-space component of the photon polarization operator is calculated in zero frequency limit for a medium with Bose-Einstein condensate (BEC) of electrically charged particles. It is found that the polarization operator tends to a finite value at vanishing photon 3-momentum, as it happens in superconducting media. It means that magnetic fields are exponentially screened in such a medium analogously to the Debye screening of electric charges. At non-zero temperature the screened magnetic field oscillates and contains a contribution which drops only as a power of distance. This phenomenon is unknown for superconductors, even in BEC phase and can be potentially observable.