项目名称： 原子系综中高度自旋压缩态产生的研究

项目编号： No.11504273

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王明锋

作者单位： 温州大学

项目金额： 20万元

中文摘要： 原子系综的自旋压缩是近年来最为热门的研究领域之一，因其在量子精密测量与量子信息处理方面有着很重要的应用。目前，已有多种压缩方案被提出，其中，非破坏性测量方案因其易于在实验上实现而备受关注。然而，由于受限于光与原子系综之间的相互作用强度，非破坏性测量方案在产生高度自旋压缩态上存在着困难。针对这一问题，本项目将在该领域展开以下三方面的研究：(1)等效的增强光与原子相互作用的研究，旨在增强相互作用的同时能抑制原子退相干，从而达到提高自旋体系压缩度的目的；(2)开发原子内态自由度用以增强体系自旋压缩度的研究，利用原子内态的压缩可贡献于体系压缩度的特点，寻找最佳的内态外态协同压缩机制；(3)非线性演化产生的研究，因非线性的单轴扭曲或双轴扭曲压缩机制有着更高的压缩效率，本研究尝试利用非破坏性测量哈密顿量构建么正演化非线性哈密顿量，从而提高体系的压缩度。

中文关键词： 压缩态；量子噪声；量子非线性；原子光学

英文摘要： Spin squeezing of atomic ensembles is one of the most active research areas in recent years due to its significant applications in quantum metrology and quantum information processing. By now, several schemes have been proposed. Among them, the approach of quantum nondemolition measurements (QND) has attracted particular attentions, because of its easier realistic implementation. However, limited by the weak coupling between light and atoms, it is quite difficult to generate highly squeezed spin state based on the QND. To solve this problem, this project will launch the research from following three aspects: (1) Find a way to effectively enhance the coupling strength, which, at the same time, can avoid the decoherence of atoms, and thus can enhance the degree of squeezing; (2) enhancing the degree of squeezing via squeezing the inner-state of atoms. Since the squeezing of the inner-state can enhance the degree of spin squeezing, we will try to find an optimal squeezing mechanism to optimize the degree of squeezing; (3) Constructing non-linear interaction. Since the one-axis and the two-axis twisting Hamiltonian can squeeze the spin state more efficiently, to increase the amount of squeezing this project will try to develop a new method to construct a unitary non-linear Hamiltonian based only on the QND interactions.

英文关键词： squeezed state;quantum noise;quantum nonlinearity;atomic optics