基于稀土离子的固态量子存储体系研究与超低温实验平台的搭建

RESEARCH ON SOLID-STATE QUANTUM STORAGE BASED ON RARE-EARTH ION DOPED CRYSTALL AND ULTRALOW EXPERIMENTAL PLATFORM CONSTRUCTION

廖奕

11930058

硕士

材料工程

钟满金

2021-05-21

2021-06-15

南方科技大学

深圳

在20世纪80年代，物理学家Feynman提出了构建以量子力学为理论基础的量子计算机，诸多后来的学者在Feynman的指引下潜心研究，使量子信息与量子计算成为科技发展的前沿领域。随着量子计算的发展，科学家们不满足于局域性的量子技术并开始思考量子计算机大规模组网的可行性，即构建量子通信网络。然而距离实现这个目标还要克服许多困难，其中之一就是实现量子信息远距离传输。输过程中不失真。稀土离子掺杂晶体具有较长的相干时间和较宽的吸收带宽，且易于扩展和集成，因此该体系在量子存储领域具有非常好的研究前景。本文重点研究了稀土离子铕（Eu3+）掺杂的硅酸钇（Y2SiO5）晶体的量子存储性能，主要着眼于铕离子退相干机制的研究，介绍了均匀展宽和非均匀展宽对体系的影响机理，以及能级寿命和相干时间的测量方法，并对相干时间的影响因素进行探究，提出延长铕离子相干时间的可行方法。此外，本文详细介绍了搭建用于稀土离子掺杂晶体量子存储实验平台的过程，重点解释超低温环境下用于固定样品的机械部件的设计工作。进一步地，为检验实验平台的有效性，我们利用该实验平台对样品进行了光谱烧孔实验，得到了铕离子的光吸收谱，并且通过激光烧孔技术测量了低温下铕离子的能级寿命T1 。在此基础上，本文对稀土离子掺杂晶体相干时间的测量实验进行远景规划并设计了用于辅助晶体样品空间位置锁定的外置磁场。

In the 1980s, American physicist Feynman proposed to build a quantum computer based on quantum mechanics. Many scholars devoted themselves to research under the guidance of Feynman, making quantum information and quantum computing the frontier of scientific and technological development. With the development of quantum computing, scientists are not satisfied with local quantum technology and have begun to think about the feasibility of large-scale networking of quantum computers, that is, building a quantum communication network. However, there are many difficulties to be overcome to achieve this goal, one of which is to achieve long-distance transmission of quantum information.The transmission carrier of quantum information is usually light, and photons are also called "flying bits". To use photons to build long-distance quantum entanglement, scientists have proposed a quantum storage method, that is, building a quantum memory that allows quantum information to be read and written to ensure that the qubit is not distorted during transmission. Rare-earth ion-doped crystals have a long coherence time and a wide absorption bandwidth. As a solid-state material, rare-earth ion-doped crystals are easy to expand and integrate. Therefore, rare-earth ion-doped crystals have a very good research prospect in the field of quantum storage.This thesis focuses on the quantum storage performance of the rare earth ion europium (Eu3+) doped yttrium silicate (Y2SiO5) crystal, aiming at the study of the decoherence mechanism of the europium ion. This thesis also introduces the mechanism of the influence of homogeneous broadening and inhomogeneous broadening on the system, the measurement methods of energy level lifetime and coherence time. I show the influencing factors of coherence time in this thesis and put forward feasible methods to extend the coherence time of europium ions. In addition, this thesis introduces in detail the process of constructing an experimental platform for rare earth ion-doped crystal quantum storage, mainly explaining the design work of sample holder used in ultra-low temperature environments. Further, to test the availability of the experimental platform, I perform a spectral hole burning experiment on the samples based on this experimental platform. The light absorption spectrum of europium ions is obtained. By spectral hole-burning, the energy level lifetime T1 of europium ions at low temperature is measured. On this basis, this paper makes a long-term plan for the measurement experiment of the coherence time of rare-earth ion-doped crystals and designs an external magnet for assisting the positioning of the crystal sample.

量子存储 稀土离子 光谱烧孔

quantum memory rare-earth ion spectral hole-burning

中文

独立培养

南方科技大学

廖奕. 基于稀土离子的固态量子存储体系研究与超低温实验平台的搭建[D]. 深圳. 南方科技大学,2021.