时间：2022年1月13日（周四） 14:00-15:30

Time：14:00-15:30, Thursday, January 13th, 2022

主持人: 西湖大学理学院讲席教授 吴从军 博士

Host：Prof. Congjun Wu, Chair Professor of School of Science, Westlake University

地点：西湖大学云栖校区4号楼311会议室

Venue：Room 311, Building 4, Yunqi Campus

主讲嘉宾/Speaker：

Prof. Ran Ni

School of Chemical and Biomedical Engineering, Nanyang Technological University (NTU)

主讲人简介/Biography:

Ran Ni is an associate professor in the School of Chemical and Biomedical Engineering in Nanyang Technological University (NTU), Singapore. He obtained his PhD of physics in 2012 from Utrecht University, the Netherlands, under the supervision of Prof. Marjolein Dijkstra, after which he did a postdoc with Profs. Martien Cohen Stuart and Peter Bolhuis from 2012 to 2014. He was awarded an NWO VENI fellowship in University of Amsterdam, which is the most prestigious personal grant for young scientists to start their independent research lines in the Netherlands. In 2016, he moved to Singapore to start his own research group in NTU. His research has been focusing on the self-assembly of colloidal and polymer systems in and out of equilibrium. He has made original contributions in dynamic assembly of active colloids, non-equilibrium hyperuniform fluids, designed assembly of DNA coated colloids, and linker-mediated vitrimers. Because of the significance of Prof. Ni’s research, he was awarded the Best Research Prize by the European Cooperation in Science and Technology (COST) Action – Flowing Matter in 2016.

讲座摘要/Abstract:

Disordered hyperuniform structures are an exotic state of matter having vanishing long wave-length density fluctuations similar to perfect crystals but without long-range order. Although its importance in materials science has been brought to the fore in the past decade, the rational design of experimentally realizable disordered strong hyperuniform micro-structures remains challenging. Here, by using computer simulations and theoretical analyses, we discover a new type of dynamic disordered fluid state with strong hyperuniformity in 2D systems of chiral active particles where particles perform independent circular motions of the radius R with the same handedness. In the strong driving or zero-noise limit, this system undergoes an absorbing-active transition to form a non-equilibrium strongly hyperuniform fluid. This new hyperuniform fluid features a special length scale, i.e., the diameter of the circular trajectory of particles, below which large density fluctuations as a result of dynamic cluster formation are observed. By developing a dynamic mean-field theory, we show that the dynamic cluster formation can be explained as an motility-induced microphase separation at mean-field level, while the Fickian diffusion at large length scales and local center of mass conserved interaction are responsible for the global hyperuniformity. Our results suggest the possibility of designing active matter system to form hierarchical disordered hyperuniform materials.

联系人/Contact:

理学院 陈老师 chenlingli@westlake.edu.cn