A High-power Spectrally Tailored Laser for High-Fidelity Quantum State Engineering in a Three-Dimensional Optical Lattice Clock*

High-fidelity quantum state control of optical qubits is crucial for quantum information science, quantum metrology, and precision interferometry. In this talk, we will present our development of a spectrally tailored laser to realize high-fidelity quantum state control when driving the optical clock transition of ⁸⁷Sr. The system leverages dual optical reference cavities—a cryogenic silicon and a room-temperature ULE—to achieve exceptional noise reduction across a broad Fourier frequency range. The frequency noise of this laser is independently verified by an atom-based spectrum analyzer utilizing an innovative pulse sequence that realizes tunable frequency sensitivity while suppressing systematic errors from laser intensity noise. We demonstrate an average single-qubit Clifford gate fidelity up to F²​=0.99964(3) while simultaneously driving 3,000 optical qubits in a three-dimensional optical lattice, measured by randomized benchmarking.