Landau-Zener-Stückelberg-Majorana (LZSM) interference has significant application value in quantum state manipulation, extending quantum state lifetime, and suppressing decoherence. Optical lattice clock, with a long coherence time, increases the likelihood of experimentally observing time-domain LZSM interference. Although time-dominant Landau-Zener (LZ) Rabi oscillations have already been observed in optical lattice clock, the time-dominant LZSM interference sidebands in optical lattice clock remain unexplored. This study is based on an 87Sr optical lattice clock. By periodically modulating the frequency of the 698-nm clock laser and optimizing the parameters of the optical clock system, LZ transitions are achieved under the fast-passage limit (FPL). During the clock detection, two acoustic optical modulators (AOMs) are employed: AOM1 that compensates for the frequency drift of the clock laser and operates continuously throughout the experiment, and AOM2 that performs traditional clock transition detection and generates a cosine modulation signal by using an external trigger from the RF signal generator in Burst mode. Ultimately, the periodically modulated 698-nm clock laser with a frequency of $\omega (t) = \cos \left[ {\displaystyle\int {\left( {{\omega _{\text{p}}} - A{\omega _{\text{s}}}\cos {\omega _{\text{s}}}t} \right){\mathrm{d}}t} } \right]$ is used to probe atoms, and the Hamiltonian is $ {\hat H_n}(t) = \dfrac{h}{2}[\delta + A{\omega _{\text{s}}}\cos ({\omega _{\text{s}}}t)]{\hat \sigma _z} + \dfrac{{h{g_n}}}{2}{\hat \sigma _x} $. As the modulated laser interacts with the atoms, the interference phenomenon is exhibited in the time domain; adjusting the clock laser detuning allows for probing the time-domain LZSM interference sideband spectra at different detection times. The results show that the time-domain LZSM interference sideband consists of multiple sidebands. Specifically, ±kth order sidebands can be observed at δ/ωs = k, where k is an integer, representing constructive interference. Additionally, due to the different LZ Rabi oscillation periods for each sideband, the excitation fractions of different sidebands are also different, resulting in different excitation fractions for sidebands at the same clock detection time. When scanning the frequency of the clock laser, small interference peaks will appear next to the +1st, +4th, +5th, +6th, –3th and –4th order sidebands when detection time is an integer period. These peaks all appear on the right side of the sidebands, thus breaking the symmetry of LZSM interference sidebands. In contrast, when the detection time is a half-integer period, the interference sidebands exhibit symmetric distribution. This phenomenon mainly arises from the effective dynamical phase accumulated during the LZSM interference evolution. Moreover, the excitation fraction is higher than that at half-integer period, which holds potential application value in state preparation research. The experimental results are in excellent agreement with theoretical simulations, confirming the feasibility of conducting time-domain LZSM interference studies on the optical lattice clock. In the future, by further suppressing clock laser noise, the optical lattice clock will provide an ideal experimental platform for studying the effects of noise on LZ transition.
DownLoad:
