Professor Li Baowen, Executive Director, NGS
- Research Works

Heat conduction and electron conduction are two fundamental energy transport phenomena in the nature. However, these two have never been treated fairly.  As we all know that the research of electron conduction has led to the invention of electronic transistor and other relevant devices that control electric flow. These inventions have led to an impressive technological development such as computer that has changed many aspects of our daily life. However, similar devices in controlling heat flow are still not available so far.

However the scenario is gradually being changed due to the pioneering works from Professor Li Baowen’s group at NUS. By using the property of temperature dependence phonon spectra of nonlinear lattices, the group has invented thermal rectifier/diode models in 2004 and 2005 (Phys. Rev. Lett,. Vol 93, 184301 (2004), Vol 95, 104302 (2005). In 2006, the theoretical model has been demonstrated experimentally by asymmetrically deposited nanotubes by Berkeley’s group (SCIENCE, Vol 314, 1121 (2006)).

Moreover, based on the new phenomenon: negative differential thermal resistance, namely the large the temperature difference the smaller the heat current, Prof. Li and his collaborators have also built up a thermal transistor model (App. Phys. Lett. Vol 88, 143501 (2006)) which controls heat flow like a Field-Effect-Transistor does for the electric current.

The invention of thermal diode and thermal transistor will pave the way for the fabrication and design of smart thermal materials which will be useful for energy saving and heat dissipation for micro and nanoscale electronic devices.

Prof. Li Baowen is leading a group of about 30 members including Ph. D students, Postdoc research fellows, visiting scientists etc. The group is working on different fields such as heat conduction in micro and nanoscale systems, complex networks in biological systems, dynamics of BEC systems, waves in complex classical and quantum systems. Due to his contribution to the understanding of heat conduction, he has been awarded: 2007 Word Scientific Medal and Prize from Singapore Institute of Physics, 2005 National Science Award, Singapore, 2005 Asia Achievement Award from Oversea’s Chinese Physics Association (OCPA), 2004 Temasek Young Investigator Award, 2003 NUS Young Researcher Award.

A list of their heat memory work (in PRL last December) has been reported by public news media as follows: