Equivalence of the Langevin and auxiliary-field quantization methods for absorbing dielectrics - art. no. 043806

Recently two methods have been developed for the quantization of the electr omagnetic field in general dispersing and absorbing linear dielectrics. The first is based upon the introduction of a quantum Langevin current in Maxw ell's equations [T. Gruner and D.-G. Welsch Phys. Rev. A 53, 1818 (1996), H o Trung Dung, L. Knoll, and D.-C. Welsch, Phys. Rev. A 57, 3931 (1998); S. Scheel, L. Knell, and D.-G. Welsch, Phys. Rev. A 58, 700 (1998)], whereas t he second makes use of a set of auxiliary fields, followed by a canonical q uantization procedure [A. Tip, Phys. Rev. A 57, 4818 (1995)]. We show that both approaches are equivalent.