Brownian fluctuations of carbon nanotube resonators

Carbon nanotube mechanical resonators hold an exceptional sensing potential, relying on their extremely low mass. As a consequence, the fundamental thermal forces are transduced into very large motion fluctuations. However, the most basic properties of these fluctuations remain poorly understood. Here we couple the motion of nanotube-based resonators to a free propagating electron beam to demonstrate that singly-clamped nanotube resonators undergo thermally-driven Brownian motion.