Abstract
Nuclear γ-ray-resonant superradiance is discussed, comparing Dicke's original approach Citation1 and recent extensions Citation2,Citation3 of Scully et al. Citation2–5 involving conditional excitation to the classical resonant-scattering Citation6–10 and the Hannon–Trammell Citation11–14 quantum theories. Relevant questions are whether the sample is optically thin or thick in the excitation and re-radiation processes, the role of superpositions between ground and excited states, Fermi's golden rule, and decoherence due to spatially-dependent near-field interactions Citation15–17. The relation of these considerations to experimental results is discussed.
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Acknowledgments
Valuable contributions by M.O. Scully, A.A. Svidzinsky and H. Lipkin are gratefully acknowledged. The author would also like to thank G.V. Smirnov for greatly improving this text through comments on an earlier version. This work was supported by the US Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Notes
Notes
1. This case does not typically appear in nuclear γ-ray resonance in matter of solid-state density.
2. This argument neglects any angular dependencies of scattering form factors.
3. Even in a symmetric reflection the presence of additional peaks besides the forward direction will increase the decay rate.