Gamma-ray emission harnessed for single photon pulses

N. A. Enaki, Marina Ţurcan, Nelly Ciobanu +2 more

John Rarity, Stephen C. Kitson, Paul R. Tapster

Aleš Stejskal, Vlastimil Vrba, Vít Procházka

We report a method for coherent control of γ-photons, enabling the shaping of γ-ray intensity in nearly arbitrary waveforms. Different intensity waveforms are created by adjusting the motion profile of a resonant absorber (an ensemble of Mössbauer nuclei) and tuning the energy of the incident radiation. A crucial aspect of this method is the use of a low fundamental frequency of vibrations, which broadens the possibilities for γ-ray control. The results of numerical simulations are experimentally validated by generating single and double γ-pulses and inducing short-term absorption. For this, a resonant absorber containing 57Fe nuclei was vibrated with different motion profiles composed of 12 harmonics with a fundamental frequency of 1 MHz. The proposed technique represents an advancement in the manipulation of γ-rays, and potentially x rays, paving the way for the performance of unique types of γ-ray or x-ray quantum experiments and the development of tools such as adjustable table-top γ-pulse sources or γ-ray or x-ray delays and gates. Moreover, inverse application of the method enables investigation of motion at the picometer scale.

I. R. Khairulin, Yevgeny V. Radeonychev, Olga A. Kocharovskaya

Abstract Recently, an observation of acoustically induced transparency (AIT) of a stainless-steel foil for resonant 14.4-keV photons from a radioactive 57Co Mössbauer source due to collective uniform oscillations of atomic nuclei was reported [Phys Rev Lett 124,163602, 2020]. In this paper, we propose to use the steep resonant dispersion of the absorber within the AIT spectral window to dramatically reduce a propagation velocity of γ-ray and x-ray photons. In particular, we show that a significant fraction (more than 40%) of a 97-ns γ-ray single-photon wave packet from a 57Co radioactive source can be slowed down up to 3 m/s and delayed by 144 ns in a 57Fe-enriched stainless-steel foil at room temperature. We also show that a similarly significant slowing down up to 24 m/s and a delay by 42 ns can be achieved for more than 70% of the 100-ns 14.4-keV x-ray single-photon pulse from a synchrotron Mössbauer source available at European Synchrotron Radiation Facility (ESRF) and Spring-8 facility. The propagation velocity can be widely controlled by changing the absorber vibration frequency. Achieving the propagation velocity on the order of 1–50 m/s would set a record in the hard x-ray range, comparable to what was obtained in the optical range.

I. R. Khairulin, V. A. Antonov, Yevgeny V. Radeonychev +1 more

Abstract The transformation of exponentially decaying waveform (the time dependence of detection probability) of a Mössbauer γ -ray photon into a regular sequence of short nearly bandwidth-limited pulses in a vibrating recoilless resonant absorber is studied. The case of dual-tone vibration at the fundamental frequency and its second harmonic under experimentally feasible conditions is considered. We show that this technique allows one to shorten pulses and increase the ratio of pulse separation to pulse length as well as to enlarge pulse amplitude compared to the pulses produced in harmonically vibrating absorber. The obtained results pave the way to the development of the time-resolved Mössbauer γ -ray spectroscopy and manipulation of quantum information in hard x-ray/ γ -ray range.