论文标题
三级量子传感中的相干控制技术
Coherent control techniques in three-level quantum sensing
论文作者
论文摘要
对具有高保真性的量子系统的量子相干控制在量子计算和量子信息处理中相当重要。有许多控制技术可以达到这些目标,例如共振激发,绝热通道,与绝热性的快捷方式等。但是,为了使一个脉搏实现人口转移,外部小误差对最终人群有微不足道的影响。相同脉冲的重复应用将极大地扩大误差效果,从而容易被检测到。在这里,我们建议使用几种相干控制技术通过相干放大效应来测量三级量子系统中的小控制误差。对于具有SU(2)动态对称性的两种类型的Hamiltonian,我们分析了种群转移的忠诚度如何受到狂犬病频率波动和静态引起的引起偏差的影响,分别基于具有交替和相同相的脉冲序列。发现检测这些误差的灵敏度可以通过控制脉冲序列有效地扩大。此外,我们通过比较最大人口概况的一半宽度来讨论通过这些控制技术传感这两个误差的效率。该结果通过反复应用相干控制脉冲,提供了一种准确且可靠的方法来感知三级量子系统中的弱误差。
Quantum coherent control of a quantum system with high-fidelity is rather important in quantum computation and quantum information processing. There are many control techniques to reach these targets, such as resonant excitation, adiabatic passages, shortcuts to adiabaticity, and so on. However, for a single pulse to realize population transfer, the external tiny error has a trivial influence on the final population. The repeated application of the same pulse will greatly amplify the error effect, making it easy to be detected. Here, we propose to measure small control errors in three-level quantum systems by coherent amplification of their effects, using several coherent control techniques. For the two types of Hamiltonian with SU(2) dynamic symmetry, we analyze how the fidelity of population transfer are affected by Rabi frequencies fluctuation and static detuning deviation, based on the pulse sequence with alternating and same phases, respectively. It is found that the sensitivity of detecting these errors can be effectively amplified by the control pulse sequences. Furthermore, we discuss the efficiency of sensing the two errors with these control techniques by comparing the full width at half maximum of the population profiles. The results provide an accurate and reliable way for sensing the weak error in three-level quantum systems by applying repeatedly the coherent control pulse.