题 目：Seeing with the nano-eye: accessing structure, function, and dynamics of matter on its natural length and time
报告人：Pro.Markus B. Raschke（美国博尔德科罗拉多大学物理系）
时 间：11月14日（周一），下午2:00-3:00
地 点：物理馆512会议室

Abstract：To understand and ultimately control the properties of most functional materials, from molecular soft-matter to quantum materials, requires access to the structure, coupling, and dynamics on the elementary time and length scales that define the microscopic interactions in these materials. To gain the desired nanometer spatial resolution with simultaneous spectroscopic specificity we combine scanning probe microscopy with different optical, including coherent, nonlinear, and ultrafast spectroscopies. The underlying near-field interaction mediated by the atomic-force or scanning tunneling microscope tip provides the desired deep-sub wavelength nano-focusing enabling few-nm spatial resolution. I will introduce our generalization of the approach in terms of the near-field impedance matching to a quantum system based on special optical antenna-tip designs. The resulting enhanced and qualitatively new forms of light-matter interaction enable measurements of quantum dynamics in an interacting environment or to image the electromagnetic local density of states of thermal radiation. Other applications include the inter-molecular coupling and dynamics in soft-matter hetero-structures, surface plasmon/phonon interferometry as a probe of electronic structure and dynamics in 2D materials, and quantum phase transitions in correlated electron materials. These examples highlight the general applicability of the new near-field microscopy approach, complementing emergent X-ray and electron imaging tools, aiming towards the ultimate goal of probing matter on its most elementary spatio-temporal level.

Short Bio：Markus Raschke is professor at the Department of Physics, Department of Chemistry, and JILA at the University of Colorado at Boulder.  His research is on the development and application of new nano-scale nonlinear and ultrafast spectroscopy techniques to imaging structure and dynamics of molecular, soft-matter, and quantum materials with nanometer spatial resolution.  He received his PhD in 2000 from the Max-Planck Institute of Quantum Optics and the Technical University in Munich, Germany. Following appointments at the University of California at Berkeley, and the Max-Born-Institute in Berlin, he became faculty member at the University of Washington, before moving to Boulder in 2010. He is fellow of the Optical Society of America and the American Physical Society.