  Based on the Landauer formalism, we demonstrate that the thermal conductance
due to the propagation of surface phonon-polaritons along a polar nanowire is
independent of the material characteristics and is given by Pi^2kB^2T/3h. The
giant propagation length of these energy carriers establishes that this
quantization holds not only for a temperature much smaller than 1 K, as is the
case of electrons and phonons, but also for temperatures comparable to room
temperature, which can significantly facilitate its observation and application
in the thermal management of nanoscale electronics and photonics.
