Ultrasensitive displacement noise measurement of carbon nanotube mechanical resonators

Mechanical resonators based on a single carbon nanotube are exceptional sensors of mass and force. The force sensitivity in these ultra-light resonators is often limited by the noise in the detection of the vibrations. Here, we report on an ultra-sensitive scheme based on a RLC resonator and a low-temperature amplifier to detect nanotube resonators. These advances in detection allow us to reach 0.5 pm/ displacement sensitivity [1]. Thermal vibrations cooled cryogenically at 300 mK are detected with a signal-to-noise ratio as high as 17 dB. We demonstrate 4.3 zN/ force sensitivity, which is the best force sensitivity achieved thus far with a mechanical resonator. This is an important step towards imaging individual nuclear spins and studying the coupling between mechanical vibrations and electrons in different quantum electron transport regimes. We will also present our recent measurements on the coupling between mechanical vibrations and electrons in the Coulomb blockade regime.


[1] S. L. De Bonis, C. Urgell, W. Yang, C. Samanta, A. Noury, J. Vergara-Cruz, Q. Dong, Y. Jin, A. Bachtold, Nano Letters, 18, 5324 (2018)