【凝聚态物理-北京大学论坛 2022年第22期(总544期)】Anomalous shifts and some nonlinear response effects
speaker: 杨声远 教授(Singapore University of Technology and Design)
place: 北京大学物理楼中212报告厅
time: 2022年10月20日(星期四) 下午3:00-4:30

  Band geometric properties play important roles in the physical properties of solids. Especially, when band near degeneracies are present near the Fermi level, there will be pronounced interband coherence effects, which manifest in quantities such as Berry curvatures and result in some interesting anomalous responses. Here, I shall talk about a few examples we studied. The first is the anomalous shift in interface scattering. It is found to be a universal effect. In Andreev reflection process, the shift can manifest the character of superconducting pairing. The second includes several nonlinear response effects. We show that they can probe band geometric properties not accessible at linear order, can be enhanced in topological metals, and can achieve unprecedented device functionalities.