NEOCLASSICAL RADIATION THEORY AS AN INTEGRAL-PART OF THE MONTE-CARLO WAVE-FUNCTION METHOD

We analyze the so-called Monte Carlo wave-function (MCWF) method from a conceptual point of view. This method has been recently introduced a s a technique to simulate dissipative processes in quantum optics. For the case where dissipation consists of spontaneous emission, we find that the coherent decay part of the MCWF method is identical to neocla ssical radiation theory. This unexpected reappearance of the neoclassi cal theory suggests the identification of the MCWF coherent decay with classical radiation reaction. It leads to an alternative interpretati on of the MCWF method instead of the usual one which is based upon qua ntum measurement theory. We give a derivation of the MCWF method, illu strated by simple Feynman diagrams, in which the appearance of radiati on reaction is shown to be a natural feature of the coherent decay par t.