Time-resolved photoemission of infinitely periodic atomic arrangements:correlation-dressed excited states of solids

A theory of the time-resolved photoemission spectroscopy(TRPES)is developed,which enables to explore the real-time electron dynamics of infinitely periodic crystalline solids.In the strongly correlated electron systems NiO and CuO,the early-stage dynamics of the valence band edge are found to be sharply contrasted between those in the spectra of TRPES.This provides a new dynamical insight to the Zaanen–Sawatzky–Allen(ZSA)classification scheme of correlated insulators and makes us assert that NiO dynamically behaves like the Mott–Hubbard insulator(MHI)and CuO like the charge transfer insulator(CTI).In the two-dimensional carbon layer graphene,the real-time electron dynamics of quantum-phase-dressed excited states,i.e.,due to the Berry phase and the pseudospin correlation,are investigated in an unprecedented way through the time-resolved angle-resolved photoemission spectroscopy(TR-ARPES).In particular,the dephasing dynamics of optically doped electrons and holes in the massless Dirac band,accompanying a field-induced gliding of the Dirac cone,are discovered.