探索发现 · 学术讲座

理解从软物质到超导体的复杂材料
Understanding complex materials from soft matter to superconductors

主讲人简介:

Alessio Zaccone is a professor of condensed matter theory in the Physics Department, University of Milan, Italy. He received his PhD from ETH Zurich in 2010 and has been on the faculty at Technical University Munich, and at University of Cambridge, before taking up his current position in 2018. His research interests include statistical physics of disordered systems, theories of amorphous solids (metallic glasses, polymeric and molecular glasses), colloidal systems, as well as granular materials, phonons and superconductivity. Prof. Zaccone has published 122 articles in peer-reviewed journals so far, including 12 papers in Physical Review Letters, 5 in PNAS, 2 in Science Advances, 1 in Nature Communications, etc.

He has received international awards, including the Gauss Professor Award for 2020 from the Göttingen Academy of Sciences, Germany and the Emerging Leader nomination by the Journal of Physics of the Institute of Physics, UK. He is known for having found an exact mathematical solution to the elasticity problem of jammed sphere packings by accounting for the nonaffine particle displacements induced by disorder (Zaccone & Scossa-Romano, PRB 2011).

讲座内容简介:

尽管安德森,莫特和范弗莱克等人很早就对无序系统中的电子行为进行研究并且因此获得了1977年诺贝尔物理学奖,但对无序和无定形系统或具有强非谐性的系统的声子和晶格动力学的类似理解仍处在非常原始的状态。由于其在当代凝聚态物理学和材料物理学中处于中心地位,该领域目前正在蓬勃发展。特别的,为了更深入地理解复杂材料(例如聚合物,金属玻璃,高温 /高压超导体),关键在于发展并健全一套具有鲁棒性的理论去描述这些复杂的凝聚态系统振动模式,软模式,非谐性和弹性/机械不稳定性[1-5]。报告的第一部分,我将简要回顾我们对包括聚合物在内的实际复杂固体中的声子和弹性的新理解。在报告第二部分,我将展示我们的理解如何形成了一个理论框架,并利用该理论框架合理地描述了无序系统中的超导性,例如金属玻璃[6]以及高压下的高温超导体。这些超导体目前在室温环境下已达到创纪录的高Tc[7-8],其中非谐性起着至关重要的作用。

While electrons in disordered systems have been studied early on leading to the Nobel prize in physics 1977 for Anderson, Mott, and van Vleck, a similar understanding of phonons and lattice dynamics of disordered and amorphous systems, or systems with strong anharmonicity, is still at its infancy. This field is currently blossoming due to its centrality in contemporary condensed matter physics and materials physics. In particular, to arrive at a deeper understanding of complex materials (e.g. polymers, metallic glasses, high-T/high-P superconductors) it is essential to develop a successful description of vibrational modes, soft modes, anharmonicity and elasticity/mechanical instabilities in these complex condensed matter systems [1-5]. I will briefly review our new understanding of phonons and elasticity in real complex solids, including polymers, from the angle of my recent contributions to the field. In the second part, I will show how this understanding can lead to a theoretical framework which describes and rationalizes superconductivity in disordered systems such as metallic glasses [6] as well as high-T superconductors at high pressures, which have currently achieved record high Tc at room temperature [7-8], and where anharmonicity plays a crucial role.

References
[1] A. Zaccone and E. Scossa-Romano, Phys. Rev. B 83, 184205 (2011)
[2] M. Baggioli and A. Zaccone, Phys. Rev. Lett. 122, 145501 (2019)
[3] M. Baggioli and A. Zaccone, Phys. Rev. Research 2, 013267 (2020)
[4] A. Zaccone and K. Trachenko, PNAS 117, 19653 (2020)
[5] A. Zaccone and M. Baggioli, PNAS 118 (5), e2022303118 (2021)
[6] M. Baggioli, C. Setty and A. Zaccone, Phys. Rev. B 101, 214502 (2020)
[7] C. Setty, M. Baggioli and A. Zaccone, Phys. Rev. B 102, 174506 (2020)
[8] C. Setty, M. Baggioli and A. Zaccone, Phys. Rev. B 103, 094519 (2021)

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