Abstract:
Mechanical resonators based on carbon nanotubes feature a series of truly exceptional properties. Carbon nanotubes are so small that they make the lightest resonators fabricated thus far. The mechanical vibrations are enormously sensitive to the dynamics of the electrons through the nanotube, and vice versa. Taking advantage of this coupling, we developed a novel detection method that allows us to measure the mechanical vibrations of nanotube resonators with an unprecedented sensitivity [1]. In this talk, I will discuss our efforts to cool the amplitude of the thermal vibrations to a few quanta [2]. Cooling is achieved using a simple yet powerful method, which consists in applying a constant (DC) current of electrons through the suspended nanotube in a dilution fridge. I will also present results where we increase the effect of the electron-phonon interaction to an unprecedented level, enabling the demonstration of polaron physics in an electro-mechanical resonator.

[1] S. L. de Bonis, C. Urgell, W. Yang, C. Samanta, A. Noury, J. Vergara-Cruz, Q. Dong, Y. Jin, A. Bachtold, Ultrasensitive Displacement Noise Measurement of Carbon Nanotube Mechanical Resonators, Nano Letters 18, 5324 (2018)

[2] C. Urgell, W. Yang, S. L. de Bonis, C. Samanta, M. J. Esplandiu, Q. Dong, Y. Jin, A. Bachtold, Cooling and Self-Oscillation in a Nanotube Electro-Mechanical Resonator, arXiv:1903.04892.