Strain engineering enhancement of surface plasmon polariton propagation lengths for gold nanowires

We present in this work the notion of using elastic strain engineering to reduce the intrinsic losses in a metal for subwavelength optical signal processing. By using a simple, analytical waveguide model, we demonstrate that application of uniaxial tensile strains below the yield strain of gold nanowires results in substantial increases of more than 70% in the surface plasmon polariton propagation lengths at optical frequencies. The enhancement is primarily due to a reduction in the core electron density, and is found to be size-independent for a wide range of nanowire diameters, while exhibiting a linear dependence on the applied tensile strain. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790293]