  We present a novel technique to remotely measure and control the local
temperature within a medium. This technique is based on the observation of the
rotational Brownian motion of gold nanocrescent particles, which possess a
strong anisotropic light interaction due to their plasmonic properties.
Rotational scattering correlation spectroscopy performed on a single
nanoparticle is able to determine the local temperature with high accuracy.
These nano-thermometers can simultaneously play the role of nano-heaters when
absorbing the light of a focused laser beam.

Mesoscale and Nanoscale Physics