Quantum Optics with Nuclear Transitions and X-ray Photons

Narrow resonances corresponding to quantum transitions in atoms, molecules, quantum dots, rare-earth ions and color centers constitute the basis of quantum optics with numerous applications in sensing, imaging, computation, communication, etc. The highest quality atomic resonances with Q-factor ~1015-1020 have been achieved in atomic clocks. Their realization requires low atomic density, vacuum environment, laser cooling below 100 nK temperature, and magnetic traps or optical lattices.
On the other hand, high quality resonances are intrinsically inherent to nuclear transitions. They do not require a deep nK cooling, are not limited to the small, diluted ensembles and offer an appealing platform for nuclear clocks, search for dark matter and time variation of the fundamental constants, gravitational and relativistic time dilation.
However, their investigation is challenging due to the absence of resonant coherent hard X-ray sources and efficient ways to control the interaction of nuclear ensembles with X-ray photons. In this talk I will review some progress in this field. It includes the experimental demonstrations of the coherent waveform shaping of the hard X-ray photons [1], acoustically induced transparency [2], slow light [3], realization of quantum nuclear memory [4,5] and resonant excitation of the 12.4 keV long-lived (0.46 s) nuclear transition in 45Sc, the most promising solid-state nuclear clock candidate [6].

[1] F.G.Vagizov , V.A. Antonov, Y.V. Radeonychev, R.N. Shakhmuratov, O. Kocharovskaya, Coherent Control of the Waveforms of Recoilless Gamma-Photons, Nature 508, 80 (2014).
[2] Y.V. Radeonychev, I.R. Khairulin, F.G. Vagizov, O. Kocharovskaya, Observation of acoustically induced transparency for gamma –ray photon, Phys. Rev. Lett. 124, 163602 (2020).
[3] I.R. Khairulin, Y.V. Radyonychev, O. Kocharovskaya, Slowing down x ray photons in a vibrating recoilless resonant absorber, Sci. Rep. 12, 20270 (2022).
[4] X. Zhang, W.-T. Liao, A.A. Kalachev, R.N. Shakhmuratov, M.O. Scully, O. Kocharovskaya, Nuclear quantum memory and time sequencing of a single γ photon, Phys. Rev. Lett. 123, 250504 (2019).
[5] S. Velten, L. Bocklage, X. Zhang, K. Schlage, A. Panchwanee, I. Sergeev, O. Leupold, A.I. Chumakov, O. Kocharovskaya, R. Röhlsberger, Science Advances, submitted.
[6] Yu. Shvyd’ko, R. Röhlsberger, O. Kocharovskaya, J. Evers et al., Resonant excitation of the long-lived 12.4-keV nuclear state in 45Sc by x-ray free-electron laser pulses -- towards Mössbauer nuclear clock, Nature 622, 471 (2023).