Quasiparticle dynamics on metal surfaces

Here we present a survey of current investigations of the quasiparticle dynamics in 2D quantum states – surface and image potential states on metal surfaces. The calculations of the lifetime of excited quasiparticle are performed within the GW approximation of many-body theory. We analyze the role of the key ingredients of the quasiparticle dynamics, namely, the screened Coulomb interaction at metal surfaces and the overlap of the initial and final states and we show that both of these factors are essential for a proper description of the quasiparticle dynamics.