The correlation of the gamma ray waveform with the vibration phase of the resonant absorber

We studied the correlation between the waveform of 14.4 keV gamma rays from a radioisotope source transmitted through a vibrational resonant absorber and the vibration phase. By transmitting 14.4 keV gamma rays emitted from a ⁵⁷Co radioisotope source through a vibrating single-line absorber, the waveform with a series of pulses can be generated. The phase of these consecutive pulses is determined by the vibration phase of the transmitting absorber at the time when the 1st excited state of ⁵⁷Fe is formed, which subsequently emits 14.4 keV gamma rays. Controlling the gamma-ray waveform has the potential to be applied to time-bin qubits and quantum memories using gamma rays and nuclear ensemble. To obtain a coherent gamma-ray waveform, synchronization between the time of formation of the 1st excited state and the vibration phase is necessary. However, achieving this synchronization is difficult because the radioactive source emits gamma rays stochastically. Therefore, we adopted the method that records all relevant information, including the vibration phase and the gamma-ray detection time. This method allows post-measurement analysis to produce waveforms corresponding to the desired vibration phases. This approach mitigates the limitations in coherent control of X-rays or gamma rays that require synchronization between the photons and the various parameters. This method is expected to advance X-ray quantum optics and quantum technology applications involving high-energy photons.