Nuclear Coherent Population Transfer with X-Ray Laser Pulses

Mehdi Amiri, M. Saadati-Niari

Mahsa Jafaridoust, Magsoud Saadati Niari, Mehdi Amiri

Xihua Yang, Z. H. Zhang, Zihan Wang +1 more

Wen-Te Liao, Adriana Pálffy, Christoph H. Keitel

The controlled transfer of nuclear state population using two x-ray laser pulses is investigated theoretically. The laser pulses drive two nuclear transitions in a nuclear three-level system facilitating coherent population transfer via the quantum optics technique of stimulated Raman adiabatic passage. To overcome present limitations of the x-ray laser frequency, we envisage accelerated nuclei interacting with two copropagating or crossed x-ray laser pulses in a three-beam setup. We present a systematic study of this setup providing both pulse temporal sequence and laser pulse intensity for optimized control of the nuclear state population. The tolerance for geometrical parameters such as laser beam divergence of the three-beam setup as well as for the velocity spread of the nuclear beam are studied and a two-photon resonance condition to account for experimental uncertainties is deduced. This additional condition gives a less strict requirement for the experimental implementation of the three-beam setup. Present experimental state of the art and future prospects are discussed.

E. Matovich

Mehdi Amiri, M. Saadati-Niari

Abstract The complete population transfer from the first state to the fifth one in a five-state nuclear system that interacts with four x-ray laser pulses has been theoretically studied using the chain-STIRAP technique. In this scheme, it is assumed that the accelerated nucleus interacts with four x-ray laser pulses, and the relativistic factor is adjusted so that the resonance condition is established between the x-ray laser frequencies and the transition frequency of the nucleus. In this study, by establishing the adiabatic condition, the Hamiltonian of the system remains in the dark state. Therefore, the second and fourth states are not populated during the time evolution. Also, to eliminate the population of the third state during the interaction, the middle pulses are considered more significant compared to the first and last pulses. For the numerical study, 168Er is considered and, it is shown that the population is completely transferred from the first state to the fifth state.