里德堡缀饰下自旋轨道耦合玻色爱因斯坦凝聚体研究
文献类型：学位论文
| 作者 | 吕昊 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 钱军 |
| 关键词 | 玻色-爱因斯坦凝聚 自旋-轨道耦合 里德堡缀饰 量子相变 |
| 其他题名 | Spin-orbit coupled Bose-Einstein condensates with Rydberg-dressing |
| 中文摘要 | 中性原子玻色-爱因斯坦凝聚体(BEC)中，离共振的里德堡激发能产生原子间的长程相互作用，它会显著地改变凝聚体的性质。本论文详细研究了拉曼光诱导人造自旋-轨道耦合和离共振里德堡激发共同作用下的双分量BEC的基态特性。主要结果概述如下： 1.当s波碰撞相互作用满足SU(2)对称性时，发现体系处于平面波相，零动量相被里德堡缀饰相互作用完全抑制。随着里德堡相互作用逐渐增强，玻色-爱因斯坦凝聚体的动量和自旋极化增大。 2.更一般地，当s波碰撞相互作用不对称时，预言了一种独特的磁性驻波（条纹）量子相，它是由权重不相同、动量相反的两个平面波分量构成。这一特殊的相与无里德堡相互作用时自旋-轨道耦合BEC中的非磁条纹相不同。本论文详细分析了里德堡相互作用对体系相图的影响。对于排斥的里德堡相互作用情形，体系可在驻波相和平面波相之间发生相变。对于吸引的里德堡相互作用情形，体系基本上处于平面波相，驻波相被里德堡相互作用抑制。 3.本论文给出了里德堡缀饰下的自旋-轨道耦合BEC的激发谱。随着里德堡相互作用增强，能隙下降。里德堡相互作用很强时激发能量出现负值，这就意味着旋子不稳定。 |
| 英文摘要 | In a Bose-Einstein condensate (BEC) with neutral atoms, off-resonant Rydberg excitation can give rise to a long-range interaction between condensate atoms, which changes the properties of the condensate remarkably. In this thesis, the ground-state properties of a binary BEC imposed by Raman-induced synthetic spin-orbit coupling and off-resonance Rydberg excitation have been investigated in detail. The main results are reviewed briefly as follows. 1.It is found that, in the case of SU(2)-invariant s-wave interactions, a plane-wave magnetic phase of the condensate emerges and the zero-momentum phase is totally suppressed by the Rydberg-dressing interaction. Furthermore, the momentum and spin polarization of the BEC increase with Rydberg interaction growing. 2.More generally, when the s-wave interactions become non-symmetric, a unique magnetic standing-wave (stripe) quantum phase composed of two plane-wave components with opposite momenta and unequal weights is predicted. The unique phase is different from the spin-orbit coupled BEC without the Rydberg interaction. The effects of the Rydberg-dressing on phase diagram of the system have been analyzed in detail. For the repulsive Rydberg-dressing interaction, the system can undergo the quantum phase transition between the plane-wave and stripe phases. However, the stripe phase is remarkably suppressed and the plane-wave phase predominates, which can be attributed to the Rydberg interaction. 3.Finally, the excitation spectrum of the spin-orbit coupled BEC with the Rydberg-dressing interaction is also presented. The energy gap is decreasing with Rydberg interaction growing and the excitation energy can be negative with strong Rydberg interaction which indicates the roton instability. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16945]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 吕昊. 里德堡缀饰下自旋轨道耦合玻色爱因斯坦凝聚体研究[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。