title: Parametric strong mode-coupling in carbon nanotube mechanical resonators.
abstract: Carbon nanotubes (CNTs) have attracted much attention for use in nanomechanical devices because of their exceptional properties, such as large resonant frequencies, low mass, and high quality factors. Here, we report the first experimental realization of parametric strong coupling between two mechanical modes on a single CNT nanomechanical resonator, by applying an extra microwave pump. This parametric pump method can be used to couple mechanical modes with arbitrary frequency differences. The properties of the mechanical resonator are detected by single-electron tunneling at low temperature, which is found to be strongly coupled to both modes. The coupling strength between the two modes can be tuned by the pump power, setting the coupling regime from weak to strong. This tunability may be useful in further phonon manipulations in carbon nanotubes.
authors.affiliation: Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China. gpguo@ustc.edu.cn gwdeng@ustc.edu.cn.
authors.forename: Shu-Xiao
authors.initials: SX
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Zhu
authors.forename: Xin-He
authors.initials: XH
authors.lastname: Wang
authors.forename: Jiang-Tao
authors.initials: JT
authors.lastname: Wang
authors.forename: Guang-Wei
authors.initials: GW
authors.lastname: Deng
authors.forename: Hai-Ou
authors.initials: HO
authors.lastname: Li
authors.forename: Gang
authors.initials: G
authors.lastname: Cao
authors.forename: Ming
authors.initials: M
authors.lastname: Xiao
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Jiang
authors.forename: Xing-Can
authors.initials: XC
authors.lastname: Dai
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Guo