-
自俘获是指波（如光波或物质波）在系统非线性作用下，克服其固有的扩散趋势，从而在极小空间尺度内传播的现象，它是理解孤子形成、局域化行为等非线性物理过程的关键。动量晶格作为一种基于超冷原子分立动量态的合成维度，在拓扑物理、局域化等方向研究表现出巨大潜力，为研究自俘获效应提供了重要的实验平台。在动量晶格中，系统的非线性来源于原子间的相互作用，这会显著影响原子在动量晶格中的动力学演化特性，诱导产生宏观自俘获的现象，然而目前基于动量晶格的自俘获现象仍处于探索阶段。本研究基于超冷铯原子动量晶格，利用Feshbach共振技术调节原子s波散射长度，测量了不同相互作用强度下系统的动力学演化行为，随着原子间相互作用的增强，原子由零动量态向高动量态的扩散行为明显受到抑制，在强相互作用区间表现出宏观自俘获现象。研究过程选择动量分布宽度d来量化分析原子的动力学特征。实验结果为基于动量晶格实现量子多体物理的研究提供了重要参考。
-
关键词:
- 玻色-爱因斯坦凝聚 /
- 动量晶格 /
- Feshbach共振 /
- 自俘获
Self-trapping, a fundamental nonlinear phenomenon in which waves overcome diffusive spreading through system nonlinearities, is essential for understanding soliton formation and wave localization. Momentum lattices, constructed from the discrete momentum states of ultracold atoms to form synthetic dimensions, provide a versatile platform for investigating topological physics and localization phenomena. In this study, we experimentally investigate interaction-induced self-trapping in a one-dimensional momentum lattice by utilizing a Bose–Einstein condensate (BEC) of cesium atoms confined in a crossed optical dipole trap. Atomic interactions are tuned via a Feshbach resonance by adjusting the s-wave scattering length $a$. The system is initially prepared in a zero-momentum state and then quenched, with the subsequent dynamics probed using time-of-flight imaging. The results show that for weak interactions ($a\approx 3a_{0}$), the atoms undergo ballistic expansion. As the scattering length $a$ increases, diffusion is suppressed, leading to macroscopic self-trapping for $a\geq 600a_{0}$, where the atoms remain localized near the zero-momentum state. Numerical simulations based on the Gross–Pitaevskii equation agree well with the experimental results and yield a critical s-wave scattering length of $a\approx 591a_{0}$. Slight deviations observed at long evolution times arise from decoherence due to spatial separation and heating. In Bogoliubov theory, the repulsive interaction in real space manifests as a local attractive potential in momentum space. This energy shift suppresses tunneling between lattice sites, inducing macroscopic self-trapping. Our findings provide valuable insights for research on quantum many-body physics in momentum lattices.-
Keywords:
- Bose-Einstein Condensate /
- Momentum Lattice /
- Feshbach Resonance /
- Selftrapping
-
[1] Celi A, Massignan P, Ruseckas J, Goldman N, Spielman I B, Juzeliunas G, Lewenstein M 2014 Phys. Rev. Lett. 112 043001.
[2] Mancini M, Pagano G, Cappellini G, Livi L, Rider M, Catani J, Sias C, Zoller P, Inguscio M, Dalmonte M, Fallani L 2015 Science 349 1510.
[3] Stuhl B K, Lu H I, Aycock L M, Genkina D, Spielman I B 2015 Science 349 1514.
[4] Anisimovas E, Raciunas M, Sträter C, Eckardt A, Spielman I B, Juzeliunas G 2016 Phys. Rev. A 94 063632.
[5] An F A, Meier E J, Gadway B 2017 Nat. Commun. 8 325.
[6] An F A, Meier E J, Ang’ong’a J, Gadway B 2018 Phys. Rev. Lett. 120 040407.
[7] Meier E J, An F A, Gadway B 2016 Nat. Commun. 7 13986.
[8] Xie D, Gou W, Xiao T, Gadway B, Yan B 2019 npj Quantum Inf. 5 55.
[9] Livi L F, Cappellini G, Diem M, Franchi L, Clivati C, Frittelli M, Levi F, Calonico D, Catani J, Inguscio M, Fallani L 2016 Phys. Rev. Lett. 117 220401.
[10] Kolkowitz S, Bromley S L, Bothwell T, Wall M L, Marti G E, Koller A P, Zhang X, Rey A M, Ye J 2017 Nature 542 66.
[11] Wall M L, Koller A P, Li S, Zhang X, Cooper N R, Ye J, Rey A M 2016 Phys. Rev. Lett. 116 035301.
[12] Price H M, Zilberberg O, Ozawa T, Carusotto I, Goldman N 2015 Phys. Rev. Lett. 115 195303.
[13] Luo X, Zhou X, Li C F, Xu J S, Guo G C, Zhou Z W 2015 Nat. Commun. 6 7704.
[14] Zilberberg O, Huang S, Guglielmon J, Wang M, Chen K P, Kraus Y E, Rechtsman M C 2018 Nature 553 59.
[15] Gadway B 2015 Phys. Rev. A 92 043606.
[16] Meier E J, An F A, Gadway B 2016 Phys. Rev. A 93 051602.
[17] Xie D Z, Gou W, Xiao T, Gadway B, Yan B 2019 npj Quantum Information 5 55.
[18] Li Y Q, Wang Y F, Zhao H X, Du H Y, Zhang J H, Hu Y, Mei F, Xiao L T, Ma J, Jia S T 2023 Physical Review Research 5 L032035.
[19] Meier E J, An F A, Dauphin A, Maffei M, Massignan P, Hughes T L, Gadway B 2018 Science 362 6417.
[20] An F A, Meier E J, Gadway B 2017 Sci. Adv. 3 e1602685.
[21] Gou W, Chen T, Xie D, Xiao T, Deng T S, Gadway B, Yi W, Yan B 2020 Phys. Rev. Lett. 124 070402.
[22] Liang Q, Xie D Z, Dong Z L, Li H W, Li H, Gadway B, Yi W, Yan B 2022 Phys. Rev. Lett. 129 070401.
[23] Wang Y F, Zhang J H, Li Y Q, Wu J Z, Liu W L, Mei F, Hu Y, Xiao L T, Ma J, Chin C, Jia S T 2022 Phys. Rev. Lett. 129 103401.
[24] Li Y Q, Du H Y, Wang Y F, Liang J J, Xiao L T, Yi W, Ma J, Jia S T 2023 Nat. Commun. 14 7560.
[25] An F A, Sundar B, Hou J P, Luo X W, Meier E J, Zhang C W, Hazzard K R A, Gadway B 2021 Phys. Rev. Lett. 127 130401.
[26] Wang Y F, Li Y Q, Wu J Z, Liu W L, Hu J Z, Ma J, Xiao L T, Jia S T 2021 Opt. Express 29 13960.
[27] Chen T, Xie D Z, Gadway B, Yan B 2021 arXiv:2103.14205v2.
[28] Chin C, Grimm R, Julienne P, Tiesinga E 2010 Rev. Mod. Phys. 82 1225.
计量
- 文章访问数: 86
- PDF下载量: 1
- 被引次数: 0
下载:
