11月21日李保文教授学术报告

报告时间:2012年11月21日（星期三下午）4:00pm-5:15pm
报告地点: 广东省显示材料与技术重点实验室一楼讲学厅
主持人：李志兵教授

报告题目：Anomalous Thermal Transport in Low Dimensional Nanostructures: from experiments to theories
报告人：Baowen Li 李保文教授

Department of Physics and Centre for Computational Science and Engineering,
National University of Singapore, Singapore 117542, Singapore

NUS-Tongji Center for Phononics and Thermal Energy Science, Department of Physics,
Tongji University, Shanghai 200092, People’s Republic of China

Abstract:

In bulk material, heat conduction is governed by Fourier’s law which is based on the assumption that phonons transport diffusively. However, for the low dimensional systems, in particular 1D systems, except for a simple harmonic oscillator chains, we don’t have any rigorous mathematical proof if the normal diffusion process can happen. Therefore it is still an open question whether the Fourier law is valid in 1D and 2D systems. Especially the sufficient and necessary condition for Fourier’s law is not clear yet .

In this talk, I will demonstrate that heat transfers in 1D and 2D systems are significantly from bulk material.

(1) Both numerically and experimentally show that thermal conductivity in 1D and/or quasi 1D system
such as nanowire and nanotube is not a constant. It depends on the system length.

(2) Thermal conductivity in single layer suspended graphene depends on the length logarithmically when the width is fixed.

In the last part, I will present our recent mathematical theory which bridges the anomalous thermal conductivity to anomalous energy diffusion