【作者】 刘颖；

【导师】 杜江峰；

【作者基本信息】 中国科学技术大学 ， 量子信息物理学， 2016， 硕士

【摘要】 金刚石氮-空穴色心因其自旋态容易被初始化与读出、能被微波射频场操控,且具有较长的相干时间,是目前量子信息与量子调控领域的热点之一。经过多年的探索与研究,在金刚石氮-空穴体系已经成功实现了很多关于量子计算、量子模拟以及量子精密测量的实验。在硕士研究期间我们开展了一系列基于金刚石氮-空穴色心体系的量子操控实验研究,并取得了一定的成果。首先是实现了对量子线拓扑绝缘体的量子相变过程进行量子模拟,直接观测到了刻画拓扑量子相变过程的拓扑数以及不同拓扑相的能级色散关系。然后是实现了室温下用单个电子自旋探测射频场。此外还参与了一些量子操控的实验,比如实现高保真度的CNOT门、在金刚石氮-空穴色心体系验证波恩规则和三个不观测量的不确定关系。本文围绕这些主题,介绍了以下内容：第一章是绪论部分,介绍了量子信息的由来,以及量子模拟以及量子精密测量的概念。第二章中介绍了金刚石氮-空穴色心体系的特征以及性质。第三章介绍了实验室自主研发的光探测磁共振平台,我们关于量子调控的实验就是在这个平台上实现的。第四章介绍了怎样用金刚石氮-空穴色心体系去对拓扑数做一个直接的观测。这是第一个对拓扑数进行直接测量的实验,我们还用量子算法求得量子线拓扑绝缘体的本征值,重构出它的能级色散关系图。第五章用单个电子自旋去探测射频场,射频场的相位、横向分量以及纵向分量都被我们观测到。由于我们的探针是单个氮-空穴色心电子自旋,所以我们可以实现亚纳米尺度的空间分辨率。第六章介绍了实现保真度高达0.992的CNOT门的实验方法与结果,这对于容错量子计算有着极大的意义。因为达到一定的保真度阈值是容错量子计算的前提条件。第七章,我们给出了总结与展望。更多还原

【Abstract】 Nitrogen-vacancy center systems are convenient to initialize and read out, have long coherence times and can be manipulated by alternating field with high precision at room temperature. Due to these good properties, NV center is the one of the most promising systems in achieving the quantum information and quantum control. In the past few years, there are many experiments successfully achieved with spins in dia-mond, including quantum computing,quantum simulating and precision measurement.I have participated in the research of quantum control based on NV center spins in diamond during the period of graduate study. We simulated the topological quantum transition of quantum wire topological insulator. Not only the topological number is obtained, but also the energy dispersion relation of different topological phases. We also achieved the detection of radio-frequency field at room temperature with a single electron spin of nitrogen-vacancy center. Besides, we implemented a quantum gate (CNOT gate) with a fidelity and verified the theories in quantum mechanic, such as Born’rule and uncertainty relation of three observables.This paper is written to introduce those works, the abstract is demonstrated as fol-low:The first chapter is to introduce the origin of quantum information and the concep-tions of quantum simulating and quantum precision measurement.The structure and properties of NV center are presented in the second chapter.In the third chapter, we introduce our home-built optical detection magnetic reso-nance platform, the experiments are carried on this platform.In the fourth chapter, we implemented the measurement of topological number of quantum transition with the spins in solid states. It is the first experiment that can obtain the topological number directly. Besides, we have reconstruct the energy dispersion relation by finding the eigenvalue of 1D quantum wire topological number.In the fifth chapter, the radio-frequency field are detected with a single electron spin in solid state. We build a solid sensor through measuring the effect of radio-frequency field on NV electron spin energy levels and the transition between them. Both of the phase and amplitude (including the transverse and longitudinal components) are measured.Reaching the threshold of fidelity is fundamental for fault-tolerant quantum com-puting. In the sixth chapter, we realized a CNOT gate with a high fidelity of 0.992.更多还原