Are there quantum beats from vacuum-induced coherence?

摘要: In a recent paper by Hegerfeldt and Plenio [1] it has been argued that for certain class of V-level systems quantum beats could be observed even if the system was not in coherent superposition upper levels. The beat frequency would different to level splitting. their analysis, this an effect vacuum field which generated levels course interaction. Their derivation is reanalyzed here using standard techniques lead master-equation. Calculating weak probe absorption spectrum, one finds — as expected experimentally accessible, physical are eigenstates combined consisting atom definition do couple. Thus, will starting from true, renormalized state therefore beating only occur initial provided.