Anomalous phonon/heat transport in low dimensional micro/nano systems

Event Details
Event Date
Speaker Name/Affiliation
Baowen Li / University of Colorado
Seminar Type/Subject
Event Details & Abstracts

When system dimension and size go down, many interesting phenomena can happen. Both experimental and numerical works in recent years have shown that phonon/heat transport in low (quasi 1D and 2D) dimensional nano structures like nanotube, nanowire, polymer chain, graphene, and other 2D materials show anomalous behavior: 
(a) heat conduction due to phonons does not follow the Fourier law; 
(b) heat transports may break down the reciprocal principle, namely heat flows asymmetrically.
(c) negative differential thermal resistance will arise, namely the larger the temperature drops, the smaller the heat current.
Issues (b) and (c) can be used to build up useful phononic thermal devices like thermal diode and thermal transistor, which lay the foundation of a new emerging field – phononics.
In this talk, I will discuss the underlying physical mechanism of these anomalous heat/phonon transport. In particular, I will discuss how the anomalous thermal transport - a macroscopic phenomenon – is connected with the anomalous energy diffusion  - a microscopic process.