报 告 人：Yaroslav V. Kartashov 教授 俄罗斯科学院光谱研究所

报告时间：2025年11月05日上午 9:00

报告地点：兴庆校区教二南楼206会议室

邀请人：电信学部李永东教授、张贻齐教授

报告摘要：Topological insulators are often considered as a new type of materials in which bulk and surface excitations exhibit qualitatively different dynamics. While excitations diffract in the depth of a topological insulator, they can propagate along its edges supporting localized edge states with energies falling into the band gap of the structure. Edge states are exponentially localized in the direction perpendicular to the boundary of the topological insulator; they propagate only along the boundary, following all its bends, and their number at a given boundary is determined by the features of the band structure and, as a rule, is equal to the topological index of the gap. The most characteristic and significant property of the edge states is their topological protection and immunity to defects, that manifests itself in the absence of backscattering or scattering into the bulk during passage of such defects. This property allows to use topological materials for construction of a new class of optical devices for processing and transmitting information, topological switches and splitters that are insensitive to defects. Over the past five years, the concept of topological insulators has expanded significantly and received considerable attention in optics, leading to the demonstration of various types of photonic topological insulators, mostly operating in the linear regime. Currently, nonlinear photonic topological insulators are under active investigation. In this presentation I will describe several types of photonic topological insulators, touch some nonlinear effects observed in them, and describe the experimental and theoretical results of our group engaged in research of such structures.

报告人简介：Yaroslav V. Kartashov 俄罗斯科学院光谱研究所教授，理论部首席科学家，曾担任西班牙光子技术研究所（ICFO）教授和Optics Letters编辑。长期从事非线性光学、数学物理以及玻色-爱因斯坦凝聚方面的研究工作，在新型非线性材料、光孤子、无衍射光、微腔极化激元等多个研究领域具有深厚的造诣，研究成果以第一/通讯作者发表在Nature、Science、Reviews of Modern Physics、Nature Reviews Physics、Nature Physics、Nature Photonics（4篇）、Physical Review Letters（46篇）等国际顶尖期刊上，个人H因子58。