2015/01/19 by Vincent Debierre, Isabelle Goessens, Édouard Brainis +1 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.92.023825
published as Phys. Rev. A 92, 023825 (2015) · 13 figures
arxiv created 2015/01/19 · arxiv updated 2015/08/26
We reconsider the problem of the spontaneous emission of light by an excited atomic state. We scrutinize the survival probability of this excited state for very short times, in the so-called Zeno regime, for which we show that the dynamics is dictated by a coherent --in phase -- response of the on-shell and off-shell vacuum modes. We also develop a perturbative approach in order to interpolate between different temporal regimes: the Zeno, golden rule (linear) and Wigner-Weisskopf (exponential) regimes. We compare results obtained with the E⋅x and A⋅p interaction Hamiltonian,s, using successively the dipole approximation and the exact coupling.