Low temperature studies of surface plasmon polaritons in silver films

We have studied propagation of surface plasmon polaritons at cryogenic temperatures and found the temperature-dependent optical loss reduction to be modest. Large temperature-independent components of the dc resistivity and the imaginary part of the dielectric constant at optical frequency are due to scattering on bulk and surface defects rather than on phonons. This suggests that the quality of metal should be improved first, after which a further improvement can be sought through the reduction of temperature. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4709751]