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Title: Time evolution, Lamb shift, and emission spectra of spontaneous emission of two identical atoms

Journal Article · · Physical Review. A
 [1];  [2];  [3];  [1]
  1. Center of Optical Sciences and Department of Physics, Chinese University of Hong Kong, N.T. (Hong Kong)
  2. Department of Physics, Hong Kong Baptist University, Kowloon Tong (Hong Kong)
  3. Department of Physics, Shanghai Jiao Tong University, Shanghai 200030 (China)

A unitary transformation method is used to investigate the dynamic evolution of two multilevel atoms, in the basis of symmetric and antisymmetric states, with one atom being initially prepared in the first excited state and the other in the ground state. The unitary transformation guarantees that our calculations are based on the ground state of the atom-field system and the self-energy is subtracted at the beginning. The total Lamb shifts of the symmetric and antisymmetric states are divided into transformed shift and dynamic shift. The transformed shift is due to emitting and reabsorbing of virtual photons, by a single atom (nondynamic single atomic shift) and between the two atoms (quasi-static shift). The dynamic shift is due to the emitting and reabsorbing of real photons, by a single atom (dynamic single atomic shift) and between the two atoms (dynamic interatomic shift). The emitting and reabsorbing of virtual and real photons between the two atoms result in the interatomic shift, which does not exist for the one-atom case. The spectra at the long-time limit are calculated. If the distance between the two atoms is shorter than or comparable to the wavelength, the strong coupling between the two atoms splits the spectrum into two peaks, one from the symmetric state and the other from the antisymmetric state. The origin of the red or blue shifts for the symmetric and antisymmetric states mainly lies in the negative or positive interaction energy between the two atoms. In the investigation of the short time evolution, we find the modification of the effective density of states by the interaction between two atoms can modulate the quantum Zeno and quantum anti-Zeno effects in the decays of the symmetric and antisymmetric states.

OSTI ID:
21408716
Journal Information:
Physical Review. A, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevA.81.043819; (c) 2010 The American Physical Society; ISSN 1050-2947
Country of Publication:
United States
Language:
English