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A glass-to-glass transition in low-temperature glasses: numerical detections of the Gardner transition |
2015-11-18
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Institute of Theoretical Physics | Chinese Academy of Sciences | State Key Laboratory of Theoretical Physics | Seminar | | Title 题目 | A glass-to-glass transition in low-temperature glasses: numerical detections of the Gardner transition | Speaker 报告人 | Yu-Liang Jin | Affiliation 所在单位 | Laboratoire de Physique Theorique, ENS, France | Date 日期 | 15:30, Nov 18 (Wednesday), 2015 | Venue 地点 | ITP New Building 6420, 理论物理研究所新楼四层多媒体教室 | Abstract 摘要 | Low-temperature crystals can be modeled as harmonic vibrations, the phonons, around a perfect lattice. The resulting Debye theory perfectly predicts thermodynamic and transport properties. Low-temperature glasses instead display all kind of anomalies with respect to this description: anomalous specific heat and thermal conductivity; activated slow dynamics across barriers inside the glass; an abundance of soft vibration modes with respect to the Debye law, the so-called Boson Peak; marginal stability of mechanical excitations; a plastic and irreversible response to arbitrarily small strain amplitudes. Here, we show that all these observations can be rationalized as the remanent of a novel phase transition—the Gardner transition—predicted by the mean field theory of glasses. The Gardner transition distinguishes between two types of amorphous solids: the simple mechanically stable glass and the marginally-stable glass. We explore numerical methods to detect the Gardner transition in several model glass formers. We show that the transition is associated to a significant growth of time and length scales, and a spatially heterogeneous organization of cages that confine particles' vibrations. We further provide concrete proposals for experiments in low-temperature glasses. |
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