Quasiparticle Interference in Trigonally Warped Graphene Systems

Lifshitz transitions and divergent density of states (DOS) in trigonally warped graphene systems have been pointed out to be responsible for the unexpected magnetism and superconductivity discovered in recent transport experiments. However, direct evidence is yet to be provided in any experiment. Here we show that quasiparticle interference, imaged by spectroscopic imaging scanning tunneling microscopy, provides direct information of the trigonally warped Fermi surfaces and hence a starting point for examining their instabilities under electron-electron interactions.