金刚石中NV色心的温度特性研究

发布时间：2017-12-30 19:13

本文关键词：金刚石中NV色心的温度特性研究　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：科技的进步使得人们的研究对象向微纳尺度发展,从而需要用量子力学来描述相关物理过程。经典的测量技术很难满足微纳尺度下的测量要求,因而推动了人们对量子测量的研究。量子测量主要利用量子力学中的量子相干或者量子统计以及量子动力学演化过程实现相关物理量的测量。选择何种量子系统作为载体成为了人们研究的重点。金刚石中的氮-空位(Nitrogen-Vacancy,NV)色心成为了固态体系中最好的候选者之一。金刚石中的NV色心具有化学惰性,在宽的温度、磁场范围以及高激光激发功率下都能保持良好的性能,而且其荧光具有良好的稳定性,在室温下具有很长的自旋相干时间。NV色心的能级能够通过微波或激光进行调控。NV色心尺寸能够做到纳米量级而且具有生物无毒性,这使得其在生物测量方面具有良好的应用前景。因而NV色心成为了量子测量研究中的优秀候选者。并且在量子通讯、量子传感、量子模拟、量子计算等多个方面具有很好地应用前景。我们进行了一系列的实验研究来了解基于NV色心实现磁场、温度场测量的机制和效果:1.我们对通用的测量二阶关联函数的方法进行了修正测量。首先我们利用PMMA掩膜和离子束注入制备了 NV色心样品,使得样品中含有便于寻找的系综NV色心标记以及在其附近的单个NV色心。利用搭建的共聚焦扫描光路来实现单个NV色心的寻址和探测。为了测量NV色心的单光子性能,我们测量了其二阶关联函数。通用的测量二阶关联函数的方法虽然简单方便,但是由于原理性的原因导致其测量的结果与理论上的二阶关联函数存在一定误差,这会影响我们对NV色心动力学演化过程的测量。为此我们提出了修正公式对通用测量方法的结果进行一定的修正,从而获得更精确的二阶关联函数。2.研究了磁场对于单个NV色心的影响,从而可以利用单个NV色心实现磁场测量。通常利用光探测磁共振技术或者冉塞条纹技术来实现对静磁场的测量,而对于交变磁场则是利用自旋回声技术来进行测量。我们主要研究的是光探测磁共振技术测量静磁场,通过对测量方法的优化可以获得较高的灵敏度。3.我们提出修改后的Varshni公式来描述NV色心的能级温度依赖特性,因而可以利用NV色心实现温度场的测量。由于目前的研究有许多是基于NV色心具有的高空间分辨率以及单光子源特性,所以我们测量了单个NV色心能级劈裂的温度依赖特性。由于金刚石材料相比半导体材料有许多特殊性质,所以导致通用的Varshni经验公式不能很好的拟合NV色心的能级随温度的变化特性。我们提出的修改后的Varshni经验公式能够在0-700K的温度范围内很好的拟合实验结果。并且对NV色心的零声子线以及金刚石中的其它缺陷结构中的能级随温度的变化趋势都能通过修改后的Varshni经验公式进行很好的拟合。这为以后研究NV色心的温度测量以及其它金刚石缺陷结构提供了很好的参考价值。4.我们利用NV色心测量了表面等离子体激元的温度特性。我们测量了 NV色心与金膜在不同的距离下的荧光寿命,发现随着距离的减小,NV色心的荧光寿命呈现指数型的减小。NV色心相互之间的耦合距离只有纳米量级,远远小于表面等离子体激元的横向传播距离。所以通过将NV色心与表面等离子体激元的耦合,可能实现远距离的NV色心之间的耦合。NV色心的荧光寿命在低温下几乎不随温度变化,当NV色心与表面等离子体激元耦合时,由于金的介电常数明显依赖于温度,所以导致NV色心感受到的局域态密度也会随温度变化。我们测量了低温下的与表面等离子体激元耦合的NV色心的荧光寿命,发现了明显的温度依赖特性。通过上面的实验研究,我们对NV色心的一些基本性质都有了较深的了解。并且对于利用NV色心实现磁场和温度场的测量也有了一定的认知。
[Abstract]:The progress of science and technology makes the research object to the development of micro nano scale, which requires a quantum mechanical description of physical process. Classic survey technique is very difficult to meet the requirements of micro nano scale measurement, thus promoting the study of quantum measurement. The main use of quantum measurement in quantum mechanics or quantum coherent quantum statistics and the quantum dynamic evolution process to measure the relevant physical quantities. The choice of a quantum system as the carrier has become the focus of research. The diamond nitrogen vacancy centers (Nitrogen-Vacancy, NV) has become one of the best candidates for solid state system. The NV color centers in diamond is chemically inert, in wide temperature, can keep the good performance of the magnetic field and high laser power excitation, and the fluorescence has good stability at room temperature with spin long coherence time.NV The center level through microwave or laser control center can achieve nanometer size.NV with biological and non-toxic, which has good application prospect in biological measurement. So the NV center has become a good candidate for the study of quantum measurement. And in quantum communication, quantum sensor, quantum simulation, multiple quantum the calculation has good application prospect. We carried out a series of experiments to understand the NV center field based on the mechanism and effect of temperature measurement methods: 1. our measure of general two order correlation function of modified measurement. First we use PMMA mask and ion beam NV color samples for the injection, the sample contains easy to find the ensemble of NV center and NV center in a single marker near. To achieve a single NV using confocal scanning optical structures Addressing and detection center. For single photon NV performance measurement center, we measured the second order correlation function method. Measuring two order correlation function universal although is simple and convenient, but due to the principle of the lead to two order correlation function of the measurement results and the theory on the existence of some errors, it will affect our measurement evolution of NV center dynamics. We proposed the correction formula of general measurement method is a correction to obtain two order correlation function of the.2. more accurate magnetic field for a single NV color effect, which can achieve the magnetic field measurement using a single NV color. Usually used to realize the measurement of static magnetic field the optical detection of magnetic resonance technology or technology for Jean plug stripes, alternating magnetic field is measured using the spin echo technique. We study the magnetic optical detection Measurement of static magnetic resonance technology, through the optimization of the measurement method can obtain higher sensitivity of.3. we propose a modified Varshni formula to describe the temperature dependence of NV center level, which can realize the measurement of temperature field using NV center. The current study has many high spatial resolution of single photon and NV centers. Based on the characteristics of the source, so we measured the single NV center level splitting temperature dependence. Because the diamond material has many special properties compared to the semiconductor material, so that the general level of Varshni empirical formula is not well fitted NV centers varies with temperature. The modified Varshni formula we proposed can result in the temperature range of 0-700K good fitting experiment. And other level defect structure of the zero phonon line of NV color center and the diamond in As the temperature changes can be modified by Varshni empirical formula fitted very well. This provides a very good reference value.4. we use NV color temperature characteristic of the surface plasmon measurement for temperature measurement of NV center and other defects of diamond structure. We measured the fluorescence lifetime of NV centers. With the gold film in different distances, was found to decrease with distance, the fluorescence lifetime of NV color center exponentially decreasing.NV center coupled to the distance between only nanometers, far less than the surface plasmon induced transverse propagation distance. So the element of NV center and surface plasmon coupled fluorescence lifetime, may the distance between the NV center coupled.NV center at low temperature hardly change with temperature, when the NV center and surface plasmon coupling, the gold The dielectric constant was dependent on the temperature, so that the local density of states of NV center feel will change with the temperature. We measured the fluorescence lifetime under low temperature and surface plasmon coupling of the NV center, found a significant temperature dependence. Through experimental studies above, some basic properties of NV centers. We have a deeper understanding. And to realize the measurement of magnetic field and temperature field by using the NV color centers also have a certain awareness.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O413

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