Quantum Fluctuations of the Refractive Index near the Interface Between a Metal and a Nonlinear Dielectric

Zero-point fluctuations of surface plasmon modes near the interface between a metal and a nonlinear dielectric are shown to produce a thin layer of shifted fluctuating dielectric constant near the interface. The shift of the dielectric constant in this layer may be sufficiently large to produce multiple metastable states of the surface plasmon vacuum.

Figure 1

(a) SP dispersion law for the cases of metal-vacuum and metal-dielectric interfaces. Nonlinear shifts of the SP resonance are shown for the cases of ${\chi }^{(3)}>0$ and ${\chi }^{(3)}<0$. (b) Geometry of quantum highway mirage observation.

Figure 2

(a) Graphic solution of Eq. (10) which defines the frequency of the SP resonance for the cases of positive and negative ${\chi }^{(3)}$ of the nonlinear optical material. The roots are shown by black dots. If ${\chi }^{(3)}$ changes sign near ${\omega }_{sp}$, all ${\chi }^{(3)}<0$ roots become metastable states of SP vacuum. (b) Vacuum bistability may be observed in a SP resonance pump-probe experiment in the Kretschman geometry. The average dielectric constant of the fluctuating interface layer can be measured by measuring the angle of the SP resonance with a weak probe beam.