论文标题
对激光捕获的$^{171} $ yb原子的旋转进动的量子非拆卸测量
Quantum Non-Demolition Measurement on the Spin Precession of Laser-Trapped $^{171}$Yb Atoms
论文作者
论文摘要
量子非拆卸（QND）测量提高了检测效率和测量保真度，并且高度期望其在精确测量和量子信息处理中的应用。我们提出并展示了激光捕获原子的自旋状态的QND测量方案。在$^{171} $ Yb原子上，将光学偶极陷阱固定在一个同时循环，自旋状态选择性和保留旋转状态的过渡是通过将圆形极化激光器的圆形光束引入激动的旋转状态，同时在地面上保持旋转状态，从而创建旋转状态。我们在20 mg的偏置磁场中测量$ 5 \ times10^{4} $原子的旋转液相位的相位。这种QND方法将光吸收检测噪声降低了$ \ sim $ 19 dB，至原子量子投射噪声的水平为2.3 dB。除了提供有效的自旋状态读数的一般方法外，这种全光学技术还允许快速切换和实时编程，以进行量子传感和量子信息处理。
Quantum non-demolition (QND) measurement enhances the detection efficiency and measurement fidelity, and is highly desired for its applications in precision measurements and quantum information processing. We propose and demonstrate a QND measurement scheme for the spin states of laser-trapped atoms. On $^{171}$Yb atoms held in an optical dipole trap, a transition that is simultaneously cycling, spin-state selective, and spin-state preserving is created by introducing a circularly polarized beam of control laser to optically dress the spin states in the excited level, while leaving the spin states in the ground level unperturbed. We measure the phase of spin precession of $5\times10^{4}$ atoms in a bias magnetic field of 20 mG. This QND approach reduces the optical absorption detection noise by $\sim$19 dB, to a level of 2.3 dB below the atomic quantum projection noise. In addition to providing a general approach for efficient spin-state readout, this all-optical technique allows quick switching and real-time programming for quantum sensing and quantum information processing.
