1. Spontaneous emission of an atom near a wedge F. S. S. Rosa Los Alamos National Laboratory Work in collaboration with T.N.C. Mendes, C. Farina and A. Tenorio

2. Plan of the talk Introduction The method An atom inside a wedge The spontaneous emission rate Final remarks

3. Introduction “A splendid light has dawned on me about the absorption and emission of radiation.” A. Einstein QED (1927) :

4. Spontaneous emission and boundary conditions - Theory P.W. Milonni and P.L. Knight (1973), M.R. Philpott (1973). G. Barton (1970), P. Stehle (1970), Parallel polarization Normal polarization

5. Experiments Feher et al. (1958) - microwave range Drexhage et al. (1968) - visible range An experiment on suppression - Jhe et al. (1987) Conducting plates Oven Beam of atoms Detector

6. The results

7. The method We use a master equation approach developed by Dalibard, Dupont-Roc and Cohen-Tannoudji to describe a particle (in our case, an atom) interacting with a reservoir (the radiation field). This approach provides general expressions for the atomic energy shifts and the exchange rates.

8. Using some reasonable approximations for the master equation, we get transition rate energy shift

9. Some important expressions } } = =

10. An atom inside a wedge R

11. The wedge has been used for some important measurements of the van der Waals force. It is the most soft departing from the plane geometry, and its relative simplicity allows some analytical calculations. To use an alternative method that gives expressions valid in both retarded and non- retarded regimes. Some Motivations

12. The excited potential

13. Graphic results  =  /3  =  /5  =  /8

14. The spontaneous emission rate

15. Graphic results

16. From another perspective

17. Suppressed emission y /2 0.24  =  /3 PP NP

18.  =  /8  =  /12 0.4 0.43 PP NP

19. Final remarks Everything seems to be working fine for the wedge setup. Refine our investigation: introduce temperature and finite conductivity effects. Investigate the possibility of trapping particles using the vacuum field.