【作者】 张华；

【导师】 陈继胜； 覃昉；

【作者基本信息】 华中师范大学 ， 凝聚态物理， 2016， 硕士

【摘要】 人们自从发现了原子中电子的自旋轨道耦合效应之后,就认识到了自旋轨道耦合对于解释物质性质的重要性。随着制冷和原子操控技术的进步,科学家们又实现了具有精细结构的超冷原子之间的人工自旋轨道耦合(synthetic spin-orbit coupling),在这样的系统中,出现了许多新奇的物理现象,为人们探索原子世界又打开了一扇门。我们以NIST (National Institute of Standards and Technology)自旋轨道耦合原子系统为研究对象,由系统的哈密顿量出发,绘制了三维三组份情况下的单粒子分布谱,进一步考虑两个精细态之间相互耦合时系统的配对状态,选取典型的两组配对方式,一组是系统质心动量为零的BCS配对态,另一组是系统具有有限质心动量的Fulde-Ferrell配对态(FF态)。在得到系统的热力学势函数的解析表达式后,利用热力学势函数取得极值的条件,找到每种态下的正常态和超流态之间的临界点,画出正常态和超流态之间的相边界线。本文的意义在于将人工自旋轨道耦合下三组份费米气体的维度由二维推广到了三维,探讨了三维情形下系统的一些相变特性。更多还原

【Abstract】 The understanding of the spin-orbit coupling effect of electrons in the atoms led to the development of condensed matter physics. As technology advances, scientists have realized synthetic spin-orbit coupling between ultracold atoms in the laboratory. There are many new physical phenomena in such a system. It’s a powerful tool for people to explore the atomic world. Spielman’s group in NIST has successfully generated synthetic SOC, which is selected as our research object. Starting from the Hamiltonian, we can obtain the single-particle dispersion spectra and then consider the coupling between two hyperfine states of the system. There are two types of pairing states, BCS state with zero center-of-mass momentum and Fulde-Ferrell (FF) pairing state with finite center-of-mass momentum. In recent years more attention has been focused on the FF pairing state. We study the phase transition property by plotting the phase boundary between the normal state and superfluidity state in a three-dimensional three-component Fermi gas with the synthetic SOC. We can get a comprehensive understanding for the physics explored in spin-orbit coupled ultracold Fermi gases.更多还原