Dreisow, F.F.DreisowHeinrich, M.M.HeinrichKeil, R.R.KeilTünnermann, A.A.TünnermannNolte, S.S.NolteLonghi, S.S.LonghiSzameit, A.A.Szameit2022-03-042022-03-042010https://publica.fraunhofer.de/handle/publica/22242910.1103/PhysRevLett.105.143902We present the first experimental realization of an optical analog for relativistic quantum mechanics by simulating the Zitterbewegung (trembling motion) of a free Dirac electron in an optical superlattice. Our photonic setting enables a direct visualization of Zitterbewegung as a spatial oscillatory motion of an optical beam. Direct measurements of the wave packet expectation values in superlattices with tuned miniband gaps clearly show the transition from weak-relativistic to relativistic and far-relativistic regimes.enwave-guide arrayoptical bloch oscillation620530journal article