Updated on 2024/10/07

写真a

 
MIYAZAKI Kunimasa
 
Organization
Graduate School of Science Professor
Graduate School
Graduate School of Science
Undergraduate School
School of Science
Title
Professor
Contact information
メールアドレス
External link

Degree 1

  1. Doctor (Science) ( 1995.3   Tokyo Institute of Technology ) 

Research Interests 3

  1. glass transition, jamming transition

  2. glass transition

  3. jamming transition

Research Areas 2

  1. Others / Others  / nonequilibrium statitical physics of soft matters

  2. Natural Science / Biophysics, chemical physics and soft matter physics

Current Research Project and SDGs 2

  1. Theory of the glass transition

  2. Nonequilibrium Statistical Mechanics

Professional Memberships 3

  1. 日本物理学会

  2. American Physical Society

  3. 日本物理学会

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Committee Memberships 4

  1. 日本学術振興会・学術システム研究センター   主任研究員  

    2022.4 - 2025.3   

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    Committee type:Academic society

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  2. The 7th International Soft Matter Conference, ISMC2023   Vice Chair  

    2020.1 - 2023.9   

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  3.   Regional Committee  

    2020.1 - 2023.8   

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  4. 28th International Conference on Statistical Physics, Statphys28   Local Organizing Committee  

    2020.1 - 2023.8   

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Papers 83

  1. Universal mechanism of shear thinning in supercooled liquids Reviewed

    Hideyuki Mizuno, Atsushi Ikeda, Takeshi Kawasaki, Kunimasa Miyazaki

    Communications Physics   Vol. 7 ( 1 )   2024.7

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    Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Abstract

    Soft glassy materials experience a significant reduction in viscosity η when subjected to shear flow, known as shear thinning. This phenomenon is characterized by a power-law scaling of η with the shear rate $$\dot{\gamma }$$, $$\eta \propto {\dot{\gamma } }^{-\nu }$$, where the exponent ν is typically around 0.7 to 0.8 across different materials. Two decades ago, the mode-coupling theory (MCT) suggested that shear thinning occurs due to the advection. However, it predicts too large ν = 1 ( > 0.7 to 0.8) and overestimates the onset shear rate by orders of magnitude. Recently, it was claimed that a minute distortion of the particle configuration is responsible for shear thinning. Here we extend the MCT to include the distortion, and find that both advection and distortion contribute to shear thinning, but the latter is dominant. Our formulation works quantitatively for several different glass formers. We explain why shear thinning is universal for many glassy materials.

    DOI: 10.1038/s42005-024-01685-8

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    Other Link: https://www.nature.com/articles/s42005-024-01685-8

  2. Unified Understanding of Nonlinear Rheology near the Jamming Transition Point Reviewed

    Takeshi Kawasaki, Kunimasa Miyazaki

    Physical Review Letters   Vol. 132 ( 26 )   2024.6

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    Publishing type:Research paper (scientific journal)   Publisher:American Physical Society (APS)  

    DOI: 10.1103/physrevlett.132.268201

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    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.132.268201/fulltext

  3. Microscopic theory for hyperuniformity in two-dimensional chiral active fluid Reviewed

    Kuroda Y., Miyazaki K.

    Journal of Statistical Mechanics: Theory and Experiment   Vol. 2023 ( 10 )   2023.10

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    Authorship:Last author   Publisher:Journal of Statistical Mechanics: Theory and Experiment  

    Some nonequilibrium systems exhibit anomalous suppression of the large-scale density fluctuations, so-called hyperuniformity. Recently, hyperuniformity was found numerically in a simple model of chiral active fluids (Lei et al 2019 Sci. Adv. 5 eaau7423). We revisit this phenomenon and put forward a microscopic theory to explain it. An effective fluctuating hydrodynamic equation is derived for a simple particle model of chiral active matter. We show that the linear analysis of the obtained hydrodynamic equation captures hyperuniformity. Our theory yields hyperuniformity characterized by the same exponents as the numerical observation, but the agreement with the numerical data is qualitative. We also argue that the hydrodynamic equation for the effective particle representation, in which each rotating trajectory is regarded as an effective particle, has the same form as the macroscopic description of the random organization model with the center of mass conservation.

    DOI: 10.1088/1742-5468/ad0639

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  4. Anomalous fluctuations in homogeneous fluid phase of active Brownian particles Reviewed

    Yuta Kuroda, Hiromichi Matsuyama, Takeshi Kawasaki, Kunimasa Miyazaki

    Physical Review Research   Vol. 5 ( 1 )   2023.2

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    Publishing type:Research paper (scientific journal)   Publisher:American Physical Society (APS)  

    DOI: 10.1103/physrevresearch.5.013077

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    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevResearch.5.013077/fulltext

  5. The Asakura-Oosawa theory: Entropic forces in physics, biology, and soft matter

    Miyazaki K., Schweizer K. S., Thirumalai D., Tuinier R., Zaccarelli E.

    JOURNAL OF CHEMICAL PHYSICS   Vol. 156 ( 8 )   2022.2

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    Language:Japanese  

    DOI: 10.1063/5.0085965

    Web of Science

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Books 1

  1. Dynamical Heterogeneity in Glass-Forming Liquids

    Biroli G., Miyazakiy K., Reichmanz D.R.

    Spin Glass Theory and Far Beyond: Replica Symmetry Breaking after 40 Years  2023.1  ( ISBN:9789811273926, 9789811273919

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    A well-known puzzle for researchers working on the glass transition problem is that a static snapshot of a supercooled liquid looks very similar to that of a high-temperature liquid. However, these two systems are very different dynamically, as their relaxation times can differ by fourteen orders of magnitude. No simple signature of this phenomenon is found in particle configurations. What has been understood in the last thirty years is that a clear signature can instead be found by looking at dynamical correlations or, expressed differently, by observing how the dynamical relaxation process unfolds in space and time.

    DOI: 10.1142/9789811273926_0010

    Scopus

MISC 11

  1. The Fredrickson-Andersen model with random pinning on Bethe lattices and its MCT transitions Reviewed

    Harukuni Ikeda, Kunimasa Miyazaki, Giulio Biroli

    EPL   Vol. 116 ( 5 ) page: 56004   2016.12

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY  

    We investigate the dynamics of the randomly pinned Fredrickson-Andersen model on the Bethe lattice. We find a line of random pinning dynamical transitions whose dynamical critical properties are in the same universality class of the A(2) and A(3) transitions of the mode coupling theory. The A(3) behavior appears at the terminal point, where the relaxation becomes logarithmic and the relaxation time diverges exponentially. We explain the critical behavior in terms of self-induced disorder and avalanches, strengthening the relationship discussed in recent works between glassy dynamics and random field Ising model. Copyright (C) EPLA, 2016

    DOI: 10.1209/0295-5075/116/56004

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  2. ガラス転移とアモルファス固体 : 最近の理論研究から—Glass transition and amorphous solids : Insights from recent theoretical studies—特集 ガラス転移を超えて,ランダム系構造・物性の進展

    池田 昌司, 水野 英如, 尾澤 岬, 宮崎 州正

    New glass   Vol. 31 ( 3 ) page: 3 - 6   2016.11

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    Language:Japanese   Publisher:ニューガラスフォーラム  

    CiNii Books

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  3. Cluster Glass Transition of Ultrasoft-Potential Fluids at High Density Reviewed

    Ryoji Miyazaki, Takeshi Kawasaki, Kunimasa Miyazaki

    PHYSICAL REVIEW LETTERS   Vol. 117 ( 16 ) page: 16570   2016.10

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:AMER PHYSICAL SOC  

    Using molecular dynamics simulation, we investigate the slow dynamics of a supercooled binary mixture of soft particles interacting with a generalized Hertzian potential. At low density, it displays typical slow dynamics near its glass transition temperature. At higher densities, particles bond together, forming clusters, and the clusters undergo the glass transition. The number of particles in a cluster increases one by one as the density increases. We demonstrate that there exist multiple cluster-glass phases characterized by a different number of particles per cluster, each of which is separated by distinct minima. Surprisingly, a so-called higher order singularity of the mode-coupling theory signaled by a logarithmic relaxation is observed in the vicinity of the boundaries between monomer and cluster glass phases. The system also exhibits rich and anomalous dynamics in the cluster glass phases, such as the decoupling of the self- and collective dynamics.

    DOI: 10.1103/PhysRevLett.117.165701

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  4. Misaki Ozawa, Kang Kim, Kunimasa Miyazaki Invited Reviewed

    Misaki Ozawa, Kang Kim, Kunimasa Miyazaki

    Journal of Statistical Mechanics: Theory and Experiment     page: 074006   2016.7

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)  

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  5. Mean-field dynamic criticality and geometric transition in the Gaussian core model Reviewed

    Daniele Coslovich, Atsushi Ikeda, Kunimasa Miyazaki

    PHYSICAL REVIEW E   Vol. 93 ( 4 ) page: 042602   2016.4

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:AMER PHYSICAL SOC  

    We use molecular dynamics simulations to investigate dynamic heterogeneities and the potential energy landscape of the Gaussian core model (GCM). Despite the nearly Gaussian statistics of particles' displacements, the GCM exhibits giant dynamic heterogeneities close to the dynamic transition temperature. The divergence of the four-point susceptibility is quantitatively well described by the inhomogeneous version of the mode-coupling theory. Furthermore, the potential energy landscape of the GCM is characterized by large energy barriers, as expected from the lack of activated, hopping dynamics, and display features compatible with a geometric transition. These observations demonstrate that all major features of mean-field dynamic criticality can be observed in a physically sound, three-dimensional model.

    DOI: 10.1103/PhysRevE.93.042602

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Presentations 205

  1. アクティブマターの非平衡物理学

    宮崎州正

    プラズマ核融合学会年会  2023.11.27 

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    Event date: 2023.11

    Presentation type:Oral presentation (invited, special)  

  2. Non-linear rheology of amorphous solids near the jamming transition point

    Takeshi Kawasaki, Kunimasa Miyazaki

    9IDMRCS, Chiba  2023.8.13 

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    Event date: 2023.8

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Chiba, Japan  

  3. Hyperuniformity in Active Particle Systems Invited

    Kunimasa Miyazaki

    2023.8.12 

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    Event date: 2023.8

    Language:English   Presentation type:Oral presentation (invited, special)  

  4. ガラス転移からアクティブマターまで ~非平衡ソフトマター理論の最前線~ Invited

    宮崎州正

    第7回 大型実験施設とスーパーコンピュータとの連携利用シンポジウム, 2021年9月14日, オンライン 

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    Event date: 2022.9

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  5. アクティブマターにおける非平衡揺らぎの長距離相関

    宮崎州正

    研究会「非平衡ソフトマター・アモルファス物質の物性解明への力学的自己組織化からの挑戦」  2022.6.23 

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    Event date: 2022.6

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Works 8

  1. メイドインジャパン物理用語 物性編 「朝倉--大澤理論」

    2010.6

  2. メイドインジャパン物理用語 物性編 「朝倉--大澤理論」

    2010.6

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  3. 宮崎州正, ``分子の世界の渋滞学 : ガラス転移の物理(第54回物性若手夏の学校(2009年度),講義ノート)" 「物性研究」 93, 956-972 (2010年6月号)

    2009.8

  4. 宮崎州正, ``分子の世界の渋滞学 : ガラス転移の物理(第54回物性若手夏の学校(2009年度),講義ノート)" 「物性研究」 93, 956-972 (2010年6月号)

    2009.8

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  5. 宮崎州正, ``ガラス転移とモード結合理論 -最近の発展と課題-" 「物性研究」 88, 621 (2007年8月号)

    2007

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KAKENHI (Grants-in-Aid for Scientific Research) 15

  1. Glass/jamming transitions of the out-of-equiilbirum systems

    Grant number:20H00128  2020.4 - 2024.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\45110000 ( Direct Cost: \34700000 、 Indirect Cost:\10410000 )

  2. Physics of Glass and Jamming Transitions Captured by Spins: from Soft Matter Physics to Statistical Physics of Information Processing

    Grant number:19H01812  2019.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Coinvestigator(s)  Grant type:Competitive

  3. Studies of the glass transtion in nonequilibrium, non-uniform, and not-standard liquids

    Grant number:16H04034  2016.4 - 2020.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Miyazaki Kunimasa

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\16900000 ( Direct Cost: \13000000 、 Indirect Cost:\3900000 )

    We carried out the conplehensive studies on the glass transition numerically and theoretically. To overcome difficulties of the conventional glass transition studies, we employed non-conventional models and settings, such as (i) novel model systems, (ii) spatially inhomogeneous systems, and (iii) the glasses out of equilibrium. We successfully showed several novel findings such as the existence of the anomalous glass phase, anomalous dimensional dependence of the slow dynamics,the thermodynamic anomalies in the vicinity of the ideal glass transition point, and the anomalous nonequilibrium phase transition in the parameter space of the shear strain and the density.

  4. 時空階層性の物理学:単純液体からソフトマターまで

    Grant number:25000002  2013 - 2018

    科学研究費助成事業  特別推進研究

    田中 肇, 荒木 武昭, 宮崎 州正, 古川 亮

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    Authorship:Coinvestigator(s)  Grant type:Competitive

    1. 水の物理に関して : (1)水の熱力学・動力学異常について研究を行い、両者が構造秩序変数そのものとそれを隣接分子まで空間的に粗視化したものによりそれぞれあらわされることを見出した。これは、両者の起源がともに局所的な正四面体構造形成に起因していることを強く示唆しており、我々の提唱する2状態モデルを強く支持する結果である。(2)また、水とシリカはともに正四面体構造をとるが、ガラス形成能に関しては、両者は極端に異なる性質を示す。その原因が、水における水素とシリカにおける酸素の空間配列の乱れの度合いの相違からきていることを発見した。2. 液体・液体転移に関して : 亜リン酸トリフェニルにおいて、液体・液体転移の可逆性を初めて明らかにするとともに、ダイナミクスを誘電緩和スペクトル測定により実時間追跡することに成功した。その結果は、我々の提唱する二秩序変数モデルの予測と一致した。3. ガラス転移現象に関して : (1)これまで局所的に安定な構造が未知であった、2成分粒子系において、局所的なパッキング能を定量化することで、隠れた構造秩序構造をあぶりだすことに成功し、温度低下とともに、その構造の相関長が動的不均一性の相関長とコヒーレントに成長することを見出した。これは、過冷却液体の示す遅いダイナミクスの背景に構造秩序の発達があるという、我々の提唱するシナリオを強く支持する結果である。(2)ガラス状態にある物質のエイジング、結晶化について研究を行い、固体ガラス状態において進行する遅い過程が、粒子の連続的な運動ではなく、雪崩的な運動により誘起されることを見出した。さらに、その背景に、粒子間の力のバランスにより自己組織的に形成される力鎖のネットワーク構造があることを見出した。(3)ずり流動下で過冷却液体の粘性が減少するいわゆるシアシニング現象の背景に、液体の構造変化があることを明らかにした。特にずりにより引き延ばされる方向の構造エントロピーが、重要な構造指標であることを発見した。4. 結晶化に関して : (1)水の新しい準安定な氷を発見し、氷の各形成において前駆体として働くことを明らかにした。(2)二つの結晶相への結晶化の競合により結晶化が阻害される原因が、その付近で結晶的な回転対称性の破れの度合いが低下し、そのため界面エネルギコストが上がり結晶核形成に対するエネルギー障壁が上がるためであることを見出した。5. 非線形流動に関して : (1)せん断流れ下にある液体の壁面でのスリップの新しい機構を発見した。(2)高密度な粉体が液体中に分散した系において、その動的な挙動が流体に非圧縮性により大きな影響を受けている証拠を見出した。6. ソフトマターに関して : (1)コロイド分散系の相分離を任意パラメータなしに数値シミュレーションにより再現することに成功するとともに、ドメインの粗大化の新しい法則を発見した。(2)多孔質中の相分離のモルフォロジーを決定する物理機構を明らかにした。(3)コロイドの濃厚分散系に存在すると信じられてきた引力ガラス状態が、実はガラスではなく、空間的な不均一性を持つゲル状態であることを見出した。(4)共焦点レーザ顕微鏡による実験により、ゲル化における運動凍結の起源がガラス化の場合と結晶化の場合があることを明らかにするとともに、それを制御している物理因子を明らかにした。以上のように液体・ソフトマターの時空階層性に関して多くの基本的な問題を解明することに成功した。

  5. Establishing the mean-field picture of the glass and jamming transitions

    Grant number:24340098  2012.4 - 2015.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    MIYAZAKI Kunimasa

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\5980000 ( Direct Cost: \4600000 、 Indirect Cost:\1380000 )

    Although the study of the glass transition of the supercooled liquids has a long history but even the mean-field picture has not been completely established yet. In this project, we have implemented extensive simulations and theoretical analysis in order to verify one of the most promising scenario of the glass mean field theory, called the RFOT. More specifically, (1) we established that the RFOT can quantitatively verify the relationship between the glass transition for liquids and the jamming transition for hard spheres, (2) we extended the so-called inhomogeneous mode-coupling theory to the system in the vicinity of the higher order singularity point, and (3) we have done the simulation for a cluster glass phase of the quasi-long ranged "ultra-soft" potential model fluids.

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Teaching Experience (On-campus) 8

  1. 非平衡物理学講究3

    2020

  2. 非平衡物理学講究1

    2020

  3. 物理学演習II

    2014

  4. 統計物理学・非線形現象論

    2014

  5. 数理物理学II

    2014

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