10/23
2020
- Title题目 (Seminar) Lattice Glass Model in Three Spatial Dimensions
- Speaker报告人
- Date日期
- Venue地点
Abstract摘要
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CAS Key Laboratory of Theoretical Physics | ||
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Institute of Theoretical Physics | ||
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Chinese Academy of Sciences | ||
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Seminar | ||
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Title 题目 |
Lattice Glass Model in Three Spatial Dimensions | |
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Speaker 报告人 |
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Affiliation 所在单位 |
Laboratoire Charles Coulomb, UMR 5221 CNRS, Université de Montpellier, 34095 Montpellier, France | |
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Date 日期 |
2020年10月23日（周五）下午16：00 | |
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Venue 地点 |
Zoom Meeting Room ID: 518 052 9336 | |
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Contact Person 所内联系人 |
雷泽 | |
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Abstract 摘要 |
Supercooled liquids and glasses are easily obtained when liquids are cooled so rapidly that first- order liquid-crystal phase transitions are avoided. Even though glasses such as window glasses around us are hard and rigid in the conventional sense, they are believed to be liquids in thermodynamics, meaning that they eventually flow in the long time limit [1] On the other hand, in “fragile” supercooled liquids showing super-Arrhenius growth in the relaxation time and viscosity, a possibility of ideal (or thermodynamic) glass transition deep inside the supercooled-liquid branch was suggested by Kauzmann in 1948 [2]. To study the possibility of thermodynamic glass transition numerically, we need to equilibrate models of fragile supercooled liquids down to very low temperature and see directly what happens there. However, due to the extremely long relaxation time and the lack of proper models that are stable enough against crystallization, we are still unable to reach low enough temperature in the supercooled-liquid branch by numerical simulations. In a recent paper [3], we proposed a three-dimensional lattice glass model on a simple cubic lattice that exhibits the typical dynamics observed in fragile supercooled liquids such as two-step relaxation, super-Arrhenius growth in the relaxation time, and dynamical heterogeneity. Using advanced Monte Carlo methods, we computed the thermodynamic properties deep inside the glassy temperature regime, well below the onset temperature of the slow dynamics. We also studied an effective free energy of glasses, the Franz–Parisi potential, as a function of the overlap between equilibrium and quenched configurations. The effective free energy indicates the existence of a first- order phase transition when a coupling field conjugate to the overlap is introduced, consistent with the random first-order transition theory. In this seminar, I will discuss the model, and its glassy dynamics and thermodynamics. [1] L. Berthier and G. Biroli, Rev. Mod. Phys. 83, 587 (2011). [2] A. W. Kauzmann, Chem. Rev. 43, 219 (1948). [3] Y. Nishikawa and K. Hukushima, Phys. Rev. Lett. 125, 065501 (2020). | |
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