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A High-Power Clock Laser Spectrally Tailored for High-Fidelity Quantum State Engineering

Atomic Physics 2025-08-29 v3

Abstract

Highly frequency-stable lasers are a ubiquitous tool for optical frequency metrology, precision interferometry, and quantum information science. While making a universally applicable laser is unrealistic, spectral noise can be tailored for specific applications. Here we report a high-power 698 nm clock laser with a maximum output of \SI{4}{W} and minimized frequency noise up to a few kHz Fourier frequency, together with long-term instability of 3.5×10173.5 \times 10^{-17} at one to thousands of seconds. The laser frequency noise is precisely characterized with atom-based spectral analysis that employs a pulse sequence designed to suppress sensitivity to intensity noise. This method provides universally applicable tunability of the spectral response and analysis of quantum sensors over a wide frequency range. With the optimized laser system characterized by this technique, we achieve an average single-qubit Clifford gate fidelity of up to F12=0.99964(3)F_1^2 = 0.99964(3) when simultaneously driving 3000 optical qubits with a homogeneous Rabi frequency ranging from \SI{10}{Hz} to \sim\SI1kHz\SI{1}{kHz}. This result represents the highest single optical-qubit gate fidelity for large number of atoms.

Keywords

Cite

@article{arxiv.2501.09343,
  title  = {A High-Power Clock Laser Spectrally Tailored for High-Fidelity Quantum State Engineering},
  author = {Lingfeng Yan and Stefan Lannig and William R. Milner and Max N. Frankel and Ben Lewis and Dahyeon Lee and Kyungtae Kim and Jun Ye},
  journal= {arXiv preprint arXiv:2501.09343},
  year   = {2025}
}