-
玻色-爱因斯坦凝聚体的涡旋研究是探索宏观量子现象的重要途径.本文聚焦于旋转双势阱中势垒参数对隐藏涡旋形成和演化的影响，旨在揭示势垒宽度和高度对涡旋动力学的调控机制.通过数值求解带耗散的Gross-Pitaevskii方程，分析了不同势垒宽度和高度下凝聚体的密度分布、相位分布、涡旋数量及平均角动量.结果表明，增加势垒宽度可以显著促进隐藏涡旋的生成，且生成的可见涡旋和隐藏涡旋总数仍然满足费曼规则；当势垒宽度较大时，隐藏涡旋会沿势垒轴线呈现摆动分布，反映隐藏涡旋间相互作用增强.相比之下，势垒高度高于临界值（指能够将凝聚体完全分隔的势垒高度）时，改变其值对生成涡旋数量影响很小；低于临界值时，隐藏涡旋核因势阱连通变得可见，而且可见涡旋的生成阈值降低.特别地，在旋转谐振子势阱中临时引入中间势垒可有效引入相位奇点，促进在较低旋转频率下生成稳定涡旋态，优于纯谐振子势阱所需的频率.本研究为实验调控涡旋提供了理论依据，具有一定的学术价值和应用前景.
-
关键词:
- 玻色-爱因斯坦凝聚体 /
- 涡旋 /
- 双势阱
Vortex dynamics in Bose-Einstein condensates (BECs) are crucial for understanding quantum coherence, superfluidity, and topological phenomena. In this work, we investigate the influence of barrier parameters in a rotating double-well potential on the formation and evolution of hidden vortices, aiming to elucidate the regulatory mechanisms of barrier width and height on vortex dynamics. By numerically solving the dissipative Gross-Pitaevskii equation for a two-dimensional BEC system confined strongly along the z-axis, we analyze the density distribution, phase distribution, vortex number, and average angular momentum under varying barrier widths and heights. The results show that increasing barrier width significantly promote the formation of hidden vortices, with the total number of visible and hidden vortices still satisfying the Feynman rule. For larger barrier widths, hidden vortices exhibite an oscillatory distribution due to enhanced vortex interactions, as shown in Fig. (a) with vortices marked by red dots. In contrast, barrier height has a limited impact on hidden vortex numbers when above a critical threshold (i.e., the height sufficient to completely separate the condensate), but below this critical threshold, hidden vortex cores become visible, reducing the threshold for vortex formation. A particularly striking finding is the efficacy of a temporary barrier strategy: by reducing V0 from 4ħωx to 0 within a rotating double-well trap, stable vortex states with four visible vortices are generated at Ω= 0.5ωx, as shown in Fig. (b). Under the same parameter conditions, it is impossible to generate a stable state containing vortices at the same Ω by directly using the rotating harmonic trap. In other words, a temporary barrier within a rotating harmonic trap effectively introduced phase singularities, facilitating stable vortex states at lower rotation frequencies than those required in a purely harmonic trap. These findings demonstrate that precise tuning of barrier parameters enables effective control of vortex states, offering theoretical guidance for experimental observation of hidden vortices and advancing the understanding of quantum vortex dynamics.-
Keywords:
- Bose-Einstein condensate /
- vortex /
- double-well potential
-
[1] Smerzi A, Fantoni S, Giovanazzi S, Shenoy S R 1997 Phys. Rev. Lett. 79 4950
[2] Albiez M, Gati R, Folling J, Hunsmann S, Cristiani M, Oberthaler M K 2005 Phys. Rev. Lett. 95 010402
[3] Hall B V, Whitlock S, Anderson R, Hannaford P, Sidorov A I 2007 Phys. Rev. Lett. 98 030402
[4] Weller A, Ronzheimer J P, Gross C, Esteve J, Oberthaler M K, Frantzeskakis D J, Theocharis G, Kevrekidis P G 2008 Phys. Rev. Lett. 101 130401
[5] Hofferberth S, Lesanovsky I, Fischer B, Verdu J, Schmiedmayer J 2006 Nature Phys. 2 710
[6] Lin Y J, Compton R L, Perry A R, Phillips W D, Porto J V, Spielman J B 2009 Phys. Rev. Lett. 102 130401
[7] Spielman I B 2009 Phys. Rev. A 79 063613
[8] Madison K W, Chevy F, Wohlleben W, Dalibard J 2000 Phys. Rev. Lett. 84 806
[9] Abo-Shaeer J R, Raman C, Vogels J M, Ketterle W 2001 Science 292 476
[10] Haljan P C, Coddington I, Engels P, Cornell E A 2001 Phys. Rev. Lett. 87 210403
[11] Hodby E, Hechenblaikner G, Hopkins S A, Marago O M, Foot C J 2001 Phys. Rev. Lett. 88 010405
[12] Zwierlein M W, Abo-Shaeer J R, Schirotzek A, Schunck C H, Ketterle W 2005 Nature (London) 435 1047
[13] Weiler C N, Neely T W, Scherer D R, Bradley A S, Davis M J, Anderson B P 2008 Nature (London) 455 948
[14] Fetter A L 2009 Rev. Mod. Phys. 81 647
[15] Cooper N R 2008 Adv. Phys. 57 539
[16] Dalfovo F, Giorgini S, Guilleumas M, Pitaevskii L, Stringari S 1997 Phys. Rev. A. 56 3840
[17] Stringari S 2001 Phys. Rev. Lett. 86 4725
[18] Penckwitt A A, Ballagh R J, Gardiner C W 2002 Phys. Rev. Lett. 89 260402
[19] Baym G, Pethick C J 2004 Phys. Rev. A 69 043619
[20] Aftalion A, Blanc X, Dalibard J 2005 Phys. Rev. A 71 023611
[21] Mizushima T, Machida K 2010 Phys. Rev. A 81 053605
[22] Ostrovskaya E A, Kivshar Y S 2004 Phys. Rev. Lett. 93 160405
[23] Piazza F, Collins L A, Smerzi A 2009 Phys. Rev. A 80 021601
[24] Wen L, Xiong H, Wu B 2010 Phys. Rev. A 82 053627
[25] Wen L, Luo X 2012 Laser Phys. Lett. 9 618
[26] Sabari S 2017 Phys. Lett. A 381 3062
[27] Ishfaq A B, Bishwajyoti D 2024 Phys. Rev. E 110 024208
[28] Wu B, Niu Q 2003 New J. Phys. 5 104
[29] Liu M, Wen L H, Xiong H W, Zhan M S 2006 Phys. Rev. A 73 063620
[30] Wen L H, Wang J S, Feng J, Hu H Q 2008 J. Phys. B 41 135301
计量
- 文章访问数: 16
- PDF下载量: 0
- 被引次数: 0
下载:
