Bose-Einstein Condensates for Gamma-Ray Lasers

S. Martellucci, M. Inguscio, Alain Aspect +1 more

Лев Абрамович Ривлин

The scenario of the experiment on the amplification of gamma rays upon stimulated transitions from metastable states of isomeric nuclei in a Bose—Einstein condensate (BEC) is presented. The experiment involves the successive transport of atoms along the so-called quantum conveyer. It is shown that if the excess broadening of the gamma-ray emission line is eliminated, the total gain G > 1 can be achieved despite the presence of negative factors such as the 'laser lethargy', spontaneous decay of metastable states, etc.

H. K. Avetissian, A. K. Avetissian, G. F. Mkrtchian

A scheme of an intense coherent gamma-ray source based on the spontaneous radiation of positronium atoms in a Bose-Einstein condensate (BEC) due to two-photon collective annihilation decay is investigated analytically arising from the second quantized formalism. It is shown that because of the intrinsic instability of annihilation decay of BEC, the spontaneously emitted entangled photon pairs are amplified, leading to an exponential buildup of a macroscopic population into end-fire modes at a certain shape of the elongated condensate. The considered scheme may also be applied to a BEC of atoms or quasiparticles as a laser mechanism with double coherence to create entangled photonic beams with a macroscopic number of photons.

Nicholas P. Robins

Лев Абрамович Ривлин, Задерновский Анатолий Андреевич

Four basic schemes for a nuclear gamma-ray laser (NGL) are analyzed using the “NGL-hyper-bola” as a generalized comparative criterion: solid state Mössbauer scheme; stimulated gamma-emission in cooled ensembles of free nuclei with hidden population inversion of nuclear states; nuclear gamma-ray lasing without inversion; and Bose-Einstein condensate as a hypothetical active medium for NGL.

Michael R. Andrews