| 研究課題/領域番号 |
20K14376
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| 研究機関 | 慶應義塾大学 |
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研究代表者 |
エドモンズ マシュー 慶應義塾大学, 自然科学研究教育センター(日吉), 訪問研究員 (00865230)
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| 研究期間 (年度) |
2020-04-01 – 2024-03-31
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| キーワード | ultracold atoms / BEC / vortices / gauge fields |
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| 研究実績の概要 |
We have theoretically examined the vortex states of a gas of trapped quasi-two-dimensional ultracold bosons subject to a density-dependent gauge potential, realizing an effective nonlinear rotation of the atomic condensate, which we also have shown is within the reach of current experimental techniques with ultracold atom experiments. The nonlinear rotation has a twofold effect; as well as distorting the shape of the condensate it also leads to an inhomogeneous vorticity resulting in unique morphological and topological states, including ring vortex arrangements that do not follow the standard Abrikosov result. The dynamics of trapped vortices are also explored.
We have explored the effect of using two-dimensional matter-wave vortices to confine an ensemble of bosonic quantum impurities. This is modelled theoretically using a mass-imbalanced homogeneous two component Gross-Pitaevskii equation where each component has independent atom numbers and equal atomic masses. By changing the mass imbalance of our system we have found the shape of the vortices are deformed even at modest imbalances, leading to barrel shaped vortices; which we have quantified using a multi-component variational approach. The energy of impurity carrying vortex pairs have been computed, revealing a mass-dependent energy splitting. We then have computed the excited states of the impurity, which we in turn have used to construct `covalent bonds' for vortex pairs. Our work opens a new route to simulating synthetic chemical reactions with superfluid systems.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Progress so far has been smooth, since two publications have been written.
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| 今後の研究の推進方策 |
I will study vortices of the second component inside a large vortex of the first component in two-component Bose-Einstein condensates.
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| 次年度使用額が生じた理由 |
Because of the COVID-19 pandemic, I could not use the grant for traveling of myself, and honorarium and travel cost for invited speakers, both of which were supposed to be the main use of the grant.
In this academic year, I plan to use it for article costs, publication fee, honorarium for speakers of online seminars, and so on.
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