Title: Materials Interface with Phase Transitions

Speaker:Prof. Junqiao Wu (University of California at Berkeley, USA)

Time:10:00am, July 20, 2012

Venue:Salon Room, Institute of Semiconductors, CAS

Abstract:Phase transitions are in the center of materials physics research. 　　 Across the two-dimensional (2D) interface between two dissimilar materials, phase transitions may behave differently from in the three-dimensional bulk. Understanding the phase transitions across materials interface would open tremendous opportunities in basic science as well as device application. In this talk I will focus on the science and application of the metal-insulator phase transition in vanadium dioxide at the surface and interface. By probing the unusual phase transition under a surface electrostatic field, we discover evidence of existence of 2D electron liquid. By interfacing vanadium dioxide with other materials, we develop a range of novel devices with unprecedented superior performance, including nanoscale solid engine that offers actuation at high speed, large amplitude and high efficiency, and power meter that can be used to directly gauge energy flow at the nano to microscale.