Linear response of embedded simple metal threads

The linear response of simple metal threads embedded in different dielectric matrices has been studied within the time-dependent local-density approximation and the jellium model. The effect of dielectric surroundings is simulated through a dielectric constant ε. In contrast to the classical theory (which holds that the dipole moment of an endless conducting cylinder does not depend on dielectric surroundings), quantum-mechanical calculations have revealed a decrease in static polarizability when a metal thread is placed in a dielectric medium. It has been found that as ε increases, the surface-plasmon resonance is red-shifted to energies below the continuum threshold and therefore can be identified easily. The behaviour of various dynamic characteristics in the vicinity of the surface-plasmon mode is discussed. The effect of the electron–electron interaction on the static polarizability and the photoabsorption is investigated.