Developing coherent states as a resource in quantum technology

在量子力学中，场的强度和相位不能同时精确地定义。在寻找描述光子相关性的数学模型时，哈佛大学的罗伊·格劳伯提出了一种光子数本征态叠加的量子态。他称这种量子态为相干态，它的相位和强度虽然在某种程度上不确定，但已经得到了很好的定义。自发现以来，相干态已经在所有物理系统中找到了一席之地，其中量子物理学涉及光学物理学快速发展的实验情况。相干态是量子物理研究的重要资源。在相干态的出现及其实验实现（理想化的激光场）之后，量子力学概念基础的实验测试才成为可能。科学各个分支的最新进展已经导致在原子水平上操纵性质--即量子工程--变得可行。相干态也是量子力学应用于信息处理以及在量子水平上控制和操纵系统的重要资源。相干态是经典物理和量子物理之间的边界，当振幅大时，相干态的相位不确定性可以忽略不计，但当振幅小时，相干态的相位不确定性很重要。在这项研究中，我们想知道相干态在量子系统的控制和操纵中所起的作用以及如何做到这一点。该项目的核心在于相干态的性质，这些相干态是为各种物理系统定义的，例如固定场，行波场，谐振子，固态系统和原子凝聚体。我们建议解决四个主要问题：1。相干态作为光运行场的操纵.稳态相干态的操纵和控制3.利用相干态探索量子世界和经典世界之间的边界4。量子技术中相干态能量来源的探讨

In quantum mechanics, the intensity and phase of a field are not simultaneously defined with perfect precision. In searching for a mathematical model to describe photon correlations, Roy Glauber at Harvard University suggested a quantum state in a superposition of photon-number eigenstates. He called this quantum state, whose phase and intensity, although uncertain to some extent, are fairly well defined, a coherent state. Since its discovery, the coherent state has found a place in all physical systems where quantum physics is involved in the rapidly evolving experimental situations of optical physics. The coherent state is an important resource for the study of quantum physics. It was after the advent of the coherent state and its experimental realisation (an idealised laser field), that experimental tests of the conceptual foundations of quantum mechanics were possible. Recent advances in various branches of science have led to a situation where the manipulation of properties at the atomic level - that is, quantum engineering-has become feasible. The coherent state is also an important resource in applications of quantum mechanics for information processing and for the control and manipulations of a system at the quantum level. The coherent state, whose uncertainty in phase is negligible when the amplitude is large, but significant when the amplitude is small, serves as a boundary between classical and quantum physics. In this investigation we want to find out the roles played by the coherent state in the control and manipulation of a quantum system and how it is done. The core of this project lies in the properties of coherent states, which are defined for various physical systems, such as a stationary field, a travelling field, a harmonic oscillator, solid-state systems and atomic condensates. We propose to address four main topics:1. Manipulation of the coherent state as an optical running field.2. Manipulation and control of a stationary coherent state 3. Exploration of the boundary between quantum and classical worlds using coherent states4. Investigation of the origin of the power of coherent states as a resource in quantum technology