Parametric strong mode-coupling in carbon nanotube mechanical resonators

TL;DR

This paper demonstrates the first experimental realization of parametric strong coupling between two mechanical modes in a single carbon nanotube resonator using microwave pumping, enabling tunable phonon interactions.

Contribution

It introduces a novel microwave pump method to achieve and control strong mode coupling in CNT resonators, expanding potential for phonon manipulation.

Findings

Strong mode coupling achieved and tunable via pump power

Coupling can be controlled from weak to strong regime

Mechanical properties detected through single-electron tunneling

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.