2017 Fiscal Year Research-status Report
Controllable Quantum Turbulence
| Project/Area Number |
16K05461
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
WHITE Angela 沖縄科学技術大学院大学, 量子システム研究ユニット, 研究員 (10750408)
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| Co-Investigator(Kenkyū-buntansha) |
BUSCH Thomas 沖縄科学技術大学院大学, 量子システム研究ユニット, 教授 (30715272)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | chaos / quantum vortices / Bose-Einstein condensate |
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| Outline of Annual Research Achievements |
We investigated chaotic vortex systems in superfluid Bose-Einstein condensates, and developed methods to exploit the finely controllable nature of Bose-Einstein condensates to engineer the onset of chaotic dynamics that are extendable to larger numbers of vortices. In addition to finding methods that reliably create chaotic vortex dynamics that are experimentally accessible, we also investigated methods that can be applied to indicate how chaotic the developing dynamics are. These methods include calculating the Lyapunov exponent and the small alignment index (SALI), which analyses the separation of a reference orbit from nearby trajectories in phase-space, as well as techniques to build up a representative picture of phase-space trajectories of individual vortices and more global measures of the whole system of vortices. We have investigated the chaotic nature of both smaller vortex-systems and systems of larger numbers of vortices. This work has established different ways of measuring the chaotic nature of vortex dynamics in condensates and provides a solid base with which to investigate the crossover from chaos to turbulence and learn about the role of chaos in turbulent quantum vortex dynamics.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We have developed techniques and now have many necessary tools to answer the key question of our research proposal, the crossover from chaotic vortex dynamics to turbulent vortex dynamics. Answering this question will allow us to gain insight to the role of chaos in turbulence, a key goal of our research proposal.
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| Strategy for Future Research Activity |
We have established and developed tools and method that will allow us to address two central aims of this research proposal which we will develop in the future: the nature of the crossover from chaotic to turbulent vortex dynamics and the role of chaos in turbulence.
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| Causes of Carryover |
We did not purchase a desktop computer and instead continued using the current desktop.
The usage plan for the next fiscal year is to use this budget for a collaborative visit as well as external storage hardware.
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