DOI: 10.1140/epjst/e2013-01921-1 THE EUROPEAN PHYSICAL JOURNAL SPECIAL TOPICS Regular Article Time resolved ultrafast ARPES for the study of topological insulators: The case of Bi2Te3

Abstract. We discuss the application of time-resolved ultrafast angle resolved photoelectron spectroscopy to the study of photoexcited topo-logical insulators. Measurements performed on the prototype material Bi2Te3 clearly show that all the main processes involved in the ultra-fast surface carrier dynamics of topological insulators can be clearly observed and quantitatively analyzed. The comparison with other ex-perimental results shows that the relative position of surface and bulk conduction bands with respect to the system Fermi level play an es-sential role in the recombination processes following ultrafast optical excitation.