Table 1: Optical and electrical properties for three metals: gold, silver, and copper.

MetalComplex refractive index (N)Mean free path ( 𝐿 𝑒 ) [ 𝜇 m ]Fermi level ( 𝐸 𝐹 ) [eV]Potential barrier ( Φ 𝐵 ) [eV]

Au0.174–j9.9600.0555.5300.780
Ag0.450–j9.2900.0575.4800.780
Cu0.145–j9.8300.0457.0500.580