Spheroidal nanoparticles as thermal near-field sensors
  We suggest to exploit the shape-dependence of the near-field heat transfer for nanoscale thermal imaging. By utilizing strongly prolate or oblate nanoparticles as sensors one can assess individual components of the correlation tensors characterizing the thermal near field close to a nanostructured surface, and thus obtain directional information beyond the local density of states. Our theoretical considerations are backed by idealized numerical model calculations. 
Svend-Age Biehs, Oliver Huth, Felix R\"uting, and Martin Holthaus
cond-mat.mes-hall