http://lqcc.ustc.edu.cn/public/inc/editer/attached/image/20150720/20150720065121_19551.jpg
Name of the speaker: GuoPing Guo
Position:Professor                                   
Organization: University of Science and Technology of China
Nationality: China
 



The Title of Speech: Strongly-coupled nanotube electromechanical resonators
Biography of the Speaker: He received a bachelor's and Ph.D. degree in physics from University of Science and Technology of China in 2000 and 2005. He joined the Department of Physics at USTC in 2005. His research focused on the exploring of quantum device of semiconductor nanostructure.
 Abstract of Speech: Carbon nanotubes (CNTs) have attracted much interest for use in nanomechanical devices because of their exceptional properties, such as large resonant frequencies, low mass, and high quality factors. By exploiting a novel micro-transfer technique, we fabricate two separate strongly-coupled and electrically-tunable mechanical resonators.
   Firstly, parametric  strong  coupling  between  two  mechanical modes on a single CNT nanomechanical resonator is realized by applying an extra microwave pump. This parametric pump method can be used to couple mechanical modes with arbitrary frequency differences. The coupling strength between the two modes can be tuned by the pump power, setting the coupling regime from weak to strong. And simulate quantum Rabi oscillations is demonstrated between two distinct mechanical modes with close resonance frequencies about 40 MHz.
   As the frequency of the two resonators can be individually tuned by the bottom gates, and in each resonator the electron transport through the quantum dot can be strongly affected by the phonon mode and vice versa. The conductance of either resonator can be nonlocally modulated by the other resonator through phonon-phonon interaction between the two resonators. Strong coupling is observed between the phonon modes of the two resonators, where the coupling strength larger than 200 kHz can be reached. This strongly-coupled nanotube electromechanical resonator array provides an experimental platform for future studies of the coherent electron-phonon interaction, the phonon mediated long-distance electron interaction, and novel nano-devices.