标题： 利用延迟脉冲检测被捕获离子的运动基态粒子数 显示英文标题

标题： Detection of motional ground state population of a trapped ion using delayed pulses

摘要： 高效制备和检测被捕获离子的运动状态在许多实验中非常重要，从量子计算到精密光谱学都涉及。我们研究了受激拉曼绝热通道（STIRAP）技术，用于捕获离子系统中运动状态的操控。所提出的技巧利用了$^{25}$Mg$^+$中两个超精细基态之间的拉曼耦合，通过延迟脉冲实现，这可以移除一个声子，而与初始运动状态无关。我们证明，对于热态，STIRAP 的种群转移比在运动侧带上的受激拉曼拉比脉冲更有效。与以前的实现不同，使用了超过跃迁自然线宽 200 倍的大失谐。这种方法使 STIRAP 适用于那些共振激光场会激发发光激发态的原子，从而妨碍 STIRAP 过程的原子。我们使用该技术测量激发运动状态与运动基态的波函数重叠。这对于光子反冲光谱学和其他利用被捕获离子运动状态对外部场高敏感性的力感应用来说是一个重要的应用。此外，确定基态种群可以简单地测量离子的温度。 显示英文摘要

摘要： Efficient preparation and detection of the motional state of trapped ions is important in many experiments ranging from quantum computation to precision spectroscopy. We investigate the stimulated Raman adiabatic passage (STIRAP) technique for the manipulation of motional states in a trapped ion system. The presented technique uses a Raman coupling between two hyperfine ground states in $^{25}$Mg$^+$, implemented with delayed pulses, which removes a single phonon independent of the initial motional state. We show that for a thermal state the STIRAP population transfer is more efficient than a stimulated Raman Rabi pulse on a motional sideband. In contrast to previous implementations, a large detuning of more than 200 times the natural linewidth of the transition is used. This approach renders STIRAP suitable for atoms in which resonant laser fields would populate fluorescing excited states and thus impede the STIRAP process. We use the technique to measure the wavefunction overlap of excited motional states with the motional ground state. This is an important application for photon recoil spectroscopy and other force sensing applications that utilize the high sensitivity of the motional state of trapped ions to external fields. Furthermore, a determination of the ground state population enables a simple measurement of the ion's temperature.