Nuclear γ-ray superradiance

Abstract

Nuclear γ-ray-resonant superradiance is discussed, comparing Dicke's original approach 1 and recent extensions 2,3 of Scully et al. 2–5 involving conditional excitation to the classical resonant-scattering 6–10 and the Hannon–Trammell 11–14 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 15–17. The relation of these considerations to experimental results is discussed.

Keywords:

• superradiance
• nuclear resonance

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.