2016 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 | quantum vortices / chaos / cold atoms |
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| Outline of Annual Research Achievements |
We aimed to study quantum turbulence in atomic Bose-Einstein condensates, answering some of the outstanding questions in the field by studying quantum vortices, in order to understand the role of chaotic events in turbulent flow. To achieve this purpose, we are building up a model of quantum turbulence by looking at the chaotic nature of few-vortex dynamics using a mean field description, which we will extend to greater numbers of vortices. During this year, we have developed a mean-field code optimised to work on the local computing cluster and are building up an analysis toolbox which we are using to learn about vortex distributions in order to determine chaotic vortex dynamics. In particular, we have tracked vortex positions, constructed histograms of individual vortex positions and computed the condensate energy spectrum. This analysis has enabled us to identify some chaotic few-vortex configurations and give a useful insight into the chaotic or regular dynamics of vortices. We will use these tools we have developed to create a controlled route towards turbulent vortex dynamics, in order to determine the conditions under which turbulence develops.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
During the first year, we have been progressing smoothly according to our research plan and have achieved the research milestones we planned to achieve. We have set up an optimised code-base and developed new analysis tools that we are successfully applying to identify different chaotic and regular vortex configurations.
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| Strategy for Future Research Activity |
In this year we will build up a more complete picture of quantum turbulence by looking at chaotic dynamics of increasing numbers of vortices that are generated in an experimentally realistic way. We will compare the vortex dynamics to a vortex filament model and continue to build on the analysis tools we have developed to enable us to identify the boundary between chaotic and turbulent vortex dynamics. Tracking important statistical measures of turbulence, such as velocity statistics and the incompressible energy spectrum will allow us to define if the vortex dynamics exhibit expected features of Kolmorogov or Vinen turbulence. By building up a controlled picture of quantum turbulence by looking at vortex configurations composed of increasing numbers of vortices, we aim to understand the role chaos plays in turbulent vortex dynamics. This procedure will help us to identify the boundary between chaos and quantum turbulence in trapped Bose-Einstein condensates and elucidate the similarities or differences to classical turbulence.
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| Causes of Carryover |
A desktop computer was not purchased as we are waiting for a new model to come out.
Research trip was cancelled due to other commitments.
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| Expenditure Plan for Carryover Budget |
Purchase a desktop computer when the new model comes out.
Organise research trip of a collaborator to OIST for collaboration on proposed research.
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