Topological Vortex Formation in BEC under Gravitational Field
| dc.creator | Kawaguchi, Yuki | |
| dc.creator | Nakahara, Mikio | |
| dc.creator | Ohmi, Tetsuo | |
| dc.date | 2004-05-17 | |
| dc.date | 2004-07-23 | |
| dc.date.accessioned | 2026-07-25T23:11:02Z | |
| dc.description | Topological phase imprinting is a unique technique for vortex formation in a Bose-Einstein condensate (BEC) of alkali metal gas, in that it does not involve rotation: BEC is trapped in a quadrupole field with a uniform bias field which is reversed adiabatically leading to vortex formation at the center of the magnetic trap. The scenario has been experimentally verified by MIT group employing $^{23}$Na atoms. Recently similar experiments have been conducted at Kyoto University, in which BEC of $^{87}$Rb atoms has been used. In the latter experiments they found that the fine-tuning of the field reverse time $T_{\rm rev}$ is required to achieve stable vortex formation. Otherwise, they often observed vortex fragmentations or a condensate without a vortex. It is shown in this paper that this behavior is attributed to the heavy mass of the Rb atom. The confining potential, which depends on the eigenvalue $m_B$ of the hyperfine spin $\bv{F}$ along the magnetic field, is now shifted by the gravitational field perpendicular to the vortex line. Then the positions of two weak-field-seeking states with $m_B=1$ and 2 deviate from each other. This effect is more prominent for BEC with a heavy atomic mass, for which the deviation is greater and, moreover, the Thomas-Fermi radius is smaller. We found, by solving the Gross-Pitaevskii equation numerically, that two condensates interact in a very complicated way leading to fragmentation of vortices, unless $T_{\rm rev}$ is properly tuned. | |
| dc.description | 7 pages, 3 figures submitted to PRA | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0405354 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0405354 | |
| dc.identifier | Phys. Rev. A 70, 043605 (2004) | |
| dc.identifier | doi:10.1103/PhysRevA.70.043605 | |
| dc.identifier.uri | https://dspace.dare.co.zw/handle/123456789/96201 | |
| dc.subject | Soft Condensed Matter | |
| dc.subject | Materials Science | |
| dc.title | Topological Vortex Formation in BEC under Gravitational Field | |
| dc.type | text |