Here I will report sideband Raman cooling and heating of longitudinal optical phonon (LOP) with a 6.23 THz frequency in semiconductor zinc telluride nano-ribbons. The ‘radiation forces’ in the Raman cooling of a LOP result from photoelastically induced Fröhlich forces, in which a long-wavelength LOP can lead to the separation of the oppositely charged atoms and thus generate a macroscopic electric field inside the crystals. The force that acts on the optical phonon will make work for the phonon oscillation. Depending on the positive or negative work that acts on the phonon, we can cool the LOP from 225 to 165 K with red-sideband pumping, but also can heat it from 230 to 326 K with a blue-sideband pumping.

[1] J. Zhang et al., Laser Cooling of a Semiconductor by 40 Kelvin, Nature (cover) 493, 504-508 (2016).

[2] J. Zhang et al., Resolved Sideband Raman Cooling of an Optical Phonon in Semiconductor Materials, Nature Photonics 10, 600-605 (2016).

报告人简介：张俊，男，博士，研究员，博士生导师。2010年在中科院半导体所获博士学位, 之后到新加坡南洋理工大学物理系从事博士后研究,2015年入选中组部第十一批“青年千人计划”，同年加入半导体超晶格国家重点实验室，任研究员和半导体声子物理课题组组长，同时兼任中国科学院大学岗位教授。张俊博士在低维半导体材料中光与声子相互作用研究，特别是半导体中声子的激光冷却和调控方面做出了一系列成果，已在国际学术期刊上发表学术论文60多篇，其包括1篇《Nature》（封面）、2篇《Nature Photonics》、7篇《Nano Letters》，撰写英文专著1章，授权专利4项。