Fully coupled dynamics of superfluid and normal fluid

• Project/Area Number: 17K05548
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Osaka City University
• Principal Investigator: Tsubota Makoto 大阪市立大学, 大学院理学研究科, 教授 (10197759)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: 量子流体力学 / 量子乱流 / 量子渦 / 超流動ヘリウム / 原子気体ボース・アインシュタイン凝縮 / 乱流 / 2流体モデル / 可視化実験 / 低温物性

Outline of Final Research Achievements

We study numerically quantum hydrodynamics and quantum turbulence.　In superfluid helium, our main result is to reveal the fully coupled dynamics of the two-fluid (superfluid and normal-fluid) model. The superfluid is described by the vortex filament mode and the normal fluid is described by the Navier-Stokes equation, and they interact through the mutual friction. Considering the thermal couterflow, we succeeded in obtaining the anomalous fluctuation of the normal fluid velocity caused by the vortex tangle; the results are qualitatively consistent with the recent visualization experiments. Another important result is observing the energy cascade of turbulence in a Bose-Einstein condensate trapped by a box potential.

Academic Significance and Societal Importance of the Research Achievements

乱流は基礎科学から応用科学まで、広い分野で研究されて来たが、未だ十分な解明には至っていない。超流動ヘリウムや原子気体BECなどの低温の量子凝縮系では、量子渦の出現に象徴されるように、通常の乱流よりも簡単な「乱流の雛形」が提供されると期待されている。本研究で得られた、超流動ヘリウムの２流体モデルにおける乱流、および原子気体BECの乱流で得られた知見は、普通の乱流の理解にも資する。

Research Products

• [Int'l Joint Research] ケンブリッジ大学(英国)
• [Int'l Joint Research] フロリダ州立大学/イエール大学(米国)
• [Int'l Joint Research] バーミンガム大学(英国)
• [Int'l Joint Research] フロリダ州立大学(米国)
• [Int'l Joint Research] 国立台湾師範大学(その他の国・地域)
• [Int'l Joint Research] フロリダ州立大学(米国)
• [Journal Article] Torque and Angular-Momentum Transfer in Merging Rotating Bose-Einstein Condensates (2020)
  • Author(s): Toshiaki Kanai, Wei Guo, Makoto Tsubota, Dafei Jin
  • Journal Title: PHYSICAL REVIEW LETTERS Volume: 124 Issue: 10
  • DOI: 10.1103/physrevlett.124.105302
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Synthetic dissipation and cascade fluxes in a turbulent quantum gas (2019)
  • Author(s): Navon Nir、Eigen Christoph、Zhang Jinyi、Lopes Raphael、Gaunt Alexander L.、Fujimoto Kazuya、Tsubota Makoto、Smith Robert P.、Hadzibabic Zoran
  • Journal Title: Science Volume: 366 Issue: 6463 Pages: 382-385
  • DOI: 10.1126/science.aau6103
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Dynamics of the Vortex-Particle Complexes Bound to the Free Surface of Superfluid Helium (2019)
  • Author(s): P. Moroshkin, P. Leiderer, K. Kono, S. Inui, M. Tsubota
  • Journal Title: PHYSICAL REVIEW LETTERS Volume: 122 Issue: 17 Pages: 174502-174502
  • DOI: 10.1103/physrevlett.122.174502
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Phase separation of quantized vortices in two-component miscible Bose-Einstein condensates in a two-dimensional box potential (2019)
  • Author(s): Junsik Han, Makoto Tsubota
  • Journal Title: Physical Review A Volume: 99 Issue: 3
  • DOI: 10.1103/physreva.99.033607
  • NAID: 120006727810
  • Peer Reviewed
• [Journal Article] Dissipation in quantum turbulence in superfluid 4He above 1 K (2018)
  • Author(s): J. Gao, W. Guo, S. Yui, M. Tsubota, W. F. Vinen
  • Journal Title: Physical Review B Volume: 97 Issue: 18
  • DOI: 10.1103/physrevb.97.184518
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Turbulence in a matter-wave supersolid (2018)
  • Author(s): C.-H. Hsueh, Y.-C. Tsai, T.-L. Horng, M. Tsubota, W. C. Wu
  • Journal Title: Physics Reports Volume: 8 Issue: 1
  • DOI: 10.1038/s41598-018-30852-5
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 量子乱流ー量子渦の非線形・非平衡ダイナミクス (2018)
  • Author(s): 坪田誠
  • Journal Title: 日本物理学会誌 Volume: 73 Pages: 474-478
  • NAID: 130007610645
  • Peer Reviewed
• [Journal Article] Three-Dimensional Coupled Dynamics of the Two-Fluid Model in Superfluid He4: Deformed Velocity Profile of Normal Fluid in Thermal Counterflow (2018)
  • Author(s): Yui Satoshi、Tsubota Makoto、Kobayashi Hiromichi
  • Journal Title: Physical Review Letters Volume: 120 Issue: 15 Pages: 155301-155301
  • DOI: 10.1103/physrevlett.120.155301
  • Peer Reviewed
• [Journal Article] Flows with fractional quantum circulation in Bose-Einstein condensates induced by nontopological phase defects (2018)
  • Author(s): Kanai Toshiaki、Guo Wei、Tsubota Makoto
  • Journal Title: Physical Review A Volume: 97 Issue: 1 Pages: 013612-013612
  • DOI: 10.1103/physreva.97.013612
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Numerical Studies of Quantum Turbulence (2017)
  • Author(s): Tsubota Makoto、Fujimoto Kazuya、Yui Satoshi
  • Journal Title: Journal of Low Temperature Physics Volume: 188 Issue: 5-6 Pages: 119-189
  • DOI: 10.1007/s10909-017-1789-8
  • Peer Reviewed
• [Presentation] Quantum Turbulence (2019)
  • Author(s): Makoto Tsubota
  • Organizer: ICFD2019: Internatinal Conference on Flow Dynamics
  • Int'l Joint Research / Invited
• [Presentation] Hydrodynamics and turbulence in quantum fluids (2019)
  • Author(s): Makoto Tsubota
  • Organizer: QFS2019: Internatinal Conference on Quantum Fluids and Solids
  • Int'l Joint Research / Invited
• [Presentation] Recent topics of quantum hydrodynamics and turbulence (2019)
  • Author(s): Makoto Tsubota
  • Organizer: Physics of Cold Atom Gases: Ordered and Chaotic Aspects
  • Int'l Joint Research / Invited
• [Presentation] 超流動4Heにおける量子渦と常流動の局所結合ダイナミクス (2019)
  • Author(s): 湯井悟志、小林宏充、坪田誠
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] 超流動4Heの量子渦タングルから放出される渦輪の統計則 (2019)
  • Author(s): 中川朋、乾聡介、坪田誠、矢野英雄
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Recent topics of quantum hydrodynamics and turbulence (2019)
  • Author(s): M. Tsubota
  • Organizer: Quantum Turbulence: Cold Atoms, Heavy Ions, and Neutron Stars
  • Int'l Joint Research / Invited
• [Presentation] Numerical Simulation of Quantum Turbulence (2018)
  • Author(s): M. Tsubota
  • Organizer: Workshop, Chasing Tornadoes: Vorticity Above, Below, and in the Lab
  • Int'l Joint Research / Invited
• [Presentation] Numerical Simulation of Quantum Turbulence (2018)
  • Author(s): Makoto Tsubota
  • Organizer: DPG Spring Meeting and EPS-CMD27
  • Int'l Joint Research / Invited
• [Presentation] Hydrodynamics and turbulence in quantum fluids (2017)
  • Author(s): Makoto Tsubota
  • Organizer: The 4th East Asia Joint Seminars on Statistical Physics
  • Int'l Joint Research / Invited
• [Presentation] Recent topics of quantum turbulence (2017)
  • Author(s): Makoto Tsubota
  • Organizer: Hybrid Photonics & Materials International Conference
  • Int'l Joint Research / Invited
• [Presentation] Fully coupled dynamics of two-fluid model in thermal counterflow: deformation of the Poiseuille normal fluid profile (2017)
  • Author(s): Makoto Tsubota, Satoshi Yui, Hiromichi Kobayashi
  • Organizer: 28th International Conference on Low Temperature Physics
  • Int'l Joint Research
• [Book] 量子流体力学 (2018)
  • Author(s): 坪田 誠、小林 未知数、竹内 宏光、笠松 健一
  • Total Pages: 338
  • Publisher: 丸善
  • ISBN: 9784621302477