Origin of optical anisotropy in noble metal (110) surfaces: theory

We study the optical anisotropy in noble metal (110) surfaces through interband transitions based on energy bands calculated through the ab initio self-consistent method of linear muffin tin orbitals. Our results show that there is indeed an important anisotropy between the imaginary parts of the dielectric constants ε⊥2(ω) and ε2‖(ω) perpendicular and parallel to the surface polarization of light, but also between εx2(ω) and εy2(ω) when light is polarized in [11̄0] and [001] crystal directions. This latter anisotropy has been measured experimentally. Here we give its theoretical origin.