Electrodynamics at non-zero temperature, chemical potential and Bose condensate

Abstract

Electrodynamics of charged scalar bosons and spin 1/2 fermions is studied at non-zero temperature, chemical potentials, and possible Bose condensate of the charged scalars. Debye screening length, plasma frequency, and the photon dispersion relation are calculated. It is found that in presence of the condensate the time-time component of the photon polarization operator in the first order in electric charge squared acquires infrared singular parts proportional to inverse powers of the spatial photon momentum k.

Field theory for a deuteron quantum liquid

“…Last but not least, in this and the next section we're discussing the effective Lagrangian at zero temperature (finite temperature effects in charged scalar condensate have been recently studied in [9]), even though what we actually have in mind is temperature much lower than the deuteron condensation temperature, but higher than the room temperature. A caution has to be exercised in this regard -at a certain temperature T e ≪ 10 −6 K (see the next section) there will be additional phase transition in which the Cooper pairs of near-the-Fermi-surface electrons will form via the Kohn-Luttinger mechanism [10] (see, [3] for a brief discussion of this effect in the presence of the BE condensate).…”

Screening effects in plasma with charged Bose condensate

“…For the calculation of the latter either imaginary or real time methods are used. However, the result can be obtained in a simpler way [10] just including into the photon Green's function the effects of medium, namely, taking not only expectation value of the time ordered product of A µ (x)A ν (y) over vacuum but add also the matter states with the weight equal to the particle distribution, f j (q), where j denotes the particle type and q is the particle momentum. The resulting expressions, found in many works -see e.g.…”

“…The resulting expressions, found in many works -see e.g. [10] and reference therein -are the following:…”

“…the potential oscillates, exponentially decreasing with distance [9,10]. This effect, however, in contrast to Friedel oscillations, does not come from the logarithmic branch point singularity in Π 00 but from the pole in the photon propagator at complex (not purely imaginary) value of k. It was shown that the polarization operator contains infrared singular term Π 00 ∼ 1/k 2 [10,11] which shifts the pole position from imaginary axis (as in Debye case) to a point with non-zero real and imaginary parts.…”

Phase transitions of charged scalars at finite temperature and chemical potential

“…Refs. [16,17] consider the screening of electric charge and photon polarization in scalar QED at finite temperature and density. Phase transitions in scalar QED with a nonzero chemical potential at zero temperature due to external magnetic fields were considered in [4].…”