Visualizing nonlinear resonance in nanomechanical systems via single-electron tunneling
carbon nanotube, mechanical resonator, quantum dot, nonlinear, coupling
Numerous reports have elucidated the importance of mechanical resonators comprising quantum-dot-embedded carbon nanotubes (CNTs) for studying the effects of single-electron transport. However, there is a need to investigate the single-electron transport that drives a large amplitude into a nonlinear regime. Herein, a CNT hybrid device has been investigated, which comprises a gate-defined quantum dot that is embedded into a mechanical resonator under strong actuation conditions. The Coulomb peak positions synchronously oscillate with the mechanical vibrations, enabling a single-electron "chopper" mode. Conversely, the vibration amplitude of the CNT versus its frequency can be directly visualized via detecting the time-averaged single-electron tunneling current. To understand this phenomenon, a general formula is derived for this time-averaged single-electron tunneling current, which agrees well with the experimental results. By using this visualization method, a variety of nonlinear motions of a CNT mechanical oscillator have been directly recorded, such as Duffing nonlinearity, parametric resonance, and double-, fractional-, mixed- frequency excitations. This approach opens up burgeoning opportunities for investigating and understanding the nonlinear motion of a nanomechanical system and its interactions with electron transport in quantum regimes.
Tsinghua University Press
Xinhe Wang, Lin Cong, Dong Zhu, Zi Yuan, Xiaoyang Lin, Weisheng Zhao, Zaiqiao Bai, Wenjie Liang, Ximing Sun, Guang-Wei Deng, Kaili Jiang. Visualizing nonlinear resonance in nanomechanical systems via single-electron tunneling. Nano Research 2021, 14(4): 1156-1161.