Exact Green’s function of photon and medium effects in QED2+1
In (2+1)-dimensional Maxwell-Chern-Simons quantum electrodynamics, we derive the structure of the exact polarization operator in the presence of medium characterized by a chemical potential μ. We show that the transverse part of the operator is the sum of four tensors. These tensors and unit one form an algebra with respect to the commutation operation. Green’s function of photons at zero temperature is derived on the basis of calculations of the oneloop form factors. The spectrum of modes is investigated. We find that the transverse and longitudinal modes exist in medium. This result differs from that of other authors. Dependence of the photon Debye mass on the form factors is investigated and a static electric potential is calculated.