Cui Jin-Ming, Ai Ming-Zhong, He Ran, Qian Zhong-Hua, Qin Xiao-Ke, Huang Yun-Feng, Zhou Zheng-Wei, Li Chuan-Feng, Tu Tao, Guo Guang-Can
CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China; CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Luoyang Institute of Electro-Optical Equipment, AVIC, Luoyang 471000, China.
Sci Bull (Beijing). 2019 Dec 15;64(23):1757-1763. doi: 10.1016/j.scib.2019.09.007. Epub 2019 Sep 10.
The geometric phase is regarded as a promising strategy in fault tolerance quantum information processing (QIP) domain due to its phase only depending on the geometry of the path executed. However, decoherence caused by environmental noise will destroy the geometric phase. Traditional dynamic decoupling sequences can eliminate dynamic dephasing but can not reduce residual geometric dephasing, which is still vital for high-precision quantum manipulation. In this work, we experimentally demonstrate effective suppression of residual geometric dephasing with modified dynamic decoupling schemes, using a single trapped Yb ion. The experimental results show that the modified schemes can reduce dephasing rate up to more than one order of magnitude compared with traditional dynamic decoupling schemes, where residual geometric dephasing dominates. Besides, we also investigate the impact of intensity and correlation time of the low-frequency noise on coherence of the quantum system. And we confirm these methods can be used in many cases.
几何相位因其仅取决于所执行路径的几何形状，而被视为容错量子信息处理（QIP）领域中一种很有前景的策略。然而，环境噪声引起的退相干会破坏几何相位。传统的动态解耦序列可以消除动态退相，但无法降低残余几何退相，而残余几何退相对于高精度量子操纵仍然至关重要。在这项工作中，我们使用单个囚禁的镱离子，通过实验证明了采用改进的动态解耦方案可有效抑制残余几何退相。实验结果表明，与传统动态解耦方案相比，在残余几何退相占主导的情况下，改进后的方案可将退相速率降低一个多数量级以上。此外，我们还研究了低频噪声的强度和相关时间对量子系统相干性的影响。并且我们证实这些方法可在多种情况下使用。
