论文标题
热气中集体自旋状态的量子动力学
Quantum Dynamics of Collective Spin States in a Thermal Gas
论文作者
论文摘要
由于其长寿命的旋转，在室温及以上在室温及以上的碱性气原子的集合被广泛应用于量子光学和计量。尽管散装和边界处有原子热运动，但他们的集体自旋状态仍保持非经典非局部相关性。在这里，我们提出了原子扩散在这些系统中的影响的随机，完全Quantum的描述。我们采用Bloch-Heisenberg-Langevin形式主义来解释源自扩散的量子噪声以及与典型壁涂层相对应的各种边界条件，从而对具有空间间相关性的非经典自旋状态的动力学进行了建模。作为示例，我们应用模型来计算自旋噪声光谱，挤压自旋态的时间松弛以及混合系统中两个自旋物种之间的相干耦合。
Ensembles of alkali or noble-gas atoms at room temperature and above are widely applied in quantum optics and metrology owing to their long-lived spins. Their collective spin states maintain nonclassical nonlocal correlations, despite the atomic thermal motion in the bulk and at the boundaries. Here we present a stochastic, fully-quantum description of the effect of atomic diffusion in these systems. We employ the Bloch-Heisenberg-Langevin formalism to account for the quantum noise originating from diffusion and from various boundary conditions corresponding to typical wall coatings, thus modeling the dynamics of nonclassical spin states with spatial inter-atomic correlations. As examples, we apply the model to calculate spin noise spectroscopy, temporal relaxation of squeezed spin states, and the coherent coupling between two spin species in a hybrid system.
