报告题目：New physics and applications of materials with metal-insulator transitions
报告人：Prof. Junqiao Wu (Department of Materials Science and Engineering, UC Berkeley)
Metal-insulator transitions arising from electron correlation or lattice reconfiguration offer a unique window to probe solid state physics, as well as a platform to design novel devices. In this talk, I will show our recent discovery on novel thermal conduction physics in the charge-density-wave material tantalum disulfide, where an unusual, temperature-independent thermal conductivity is found and attributed to strong electron-phonon coupling that dominates over the conventional phonon-phonon scattering. I will also discuss how we engineer vanadium dioxide for novel device applications: by grading or meta-structuring its metal-insulator phase transition, we demonstrate temperature-indepdendent thermal radiation which is used for a superior infrared camouflage and decoy, high temperature-coefficient of resistivity for infrared detection, high sensitivity to ionic strength of solutions for chemically powered neumorphic computing, as well as switchable thermal radiation used for thermal imaging gradient enhancing and smart radiative cooling.
Professor Junqiao Wu received a B.S. from Fudan University and a M.S. from Peking University, China. He obtained a Ph.D. degree from the University of California, Berkeley, and did postdoctoral research at Harvard University. He is currently a full professor at the Department of Materials Science and Engineering, and the Chair of the Applied Science and Technology Graduate Group at UC Berkeley, and also holds joint appointment at the Lawrence Berkeley National Laboratory. His honors include the 29th Ross N. Tucker Memorial Award, the US-NSF Career Award, the US-DOE Early Career Award, the Presidential Early Career Award for Scientists and Engineers (PECASE) from the White House, the Outstanding Alumni Award from Peking University China, and the Fellow of APS. The Wu group explores novel properties and applications of nanomaterials, phase transitions at the nanoscale, and optoelectronic, thermal and thermoelectric properties of electronic materials. Prof. Wu has published over 200 widely cited papers in these fields. For more details, visit https://wu.mse.berkeley.edu/.