A. Sterzi

Ultrafast Optical Control of the Electronic Properties of ZrTe5

We report on the temperature dependence of the ZrTe(5) electronic properties, studied at equilibrium and out of equilibrium, by means of time and angle resolved photoelectron spectroscopy. Our results unveil the dependence of the electronic band structure across the Fermi energy on the sample temperature. This finding is regarded as the dominant mechanism responsible for the anomalous resistivity observed at T*∼160  K along with the change of the charge carrier character from holelike to electronlike. Having addressed these long-lasting questions, we prove the possibility to control, at the ultrashort time scale, both the binding energy and the quasiparticle lifetime of the valence band. These experimental evidences pave the way for optically controlling the thermoelectric and magnetoelectric transport properties of ZrTe(5).

Dynamics of correlation-frozen antinodal quasiparticles in superconducting cuprates

\mathrm{MoTe_2}

Evidence for a Strong Topological Insulator Phase in ZrTe5

has recently been shown to realize in its low-temperature phase the type-II Weyl semimetal (WSM). We investigated by time- and angle- resolved photoelectron spectroscopy (tr-ARPES) the possible influence of the Weyl points in the electron dynamics above the Fermi level

Bulk diffusive relaxation mechanisms in optically excited topological insulators

\mathrm{E_F}

Persistence of a surface state arc in the topologically trivial phase of MoTe2

, by comparing the ultrafast response of

SmB6 electron-phonon coupling constant from time- and angle-resolved photoelectron spectroscopy

\mathrm{MoTe_2}

Advancing non-equilibrium ARPES experiments by a 9.3 eV coherent ultrafast photon source

in the trivial and topological phases. In the low-temperature WSM phase, we report an enhanced relaxation rate of electrons optically excited to the conduction band, which we interpret as a fingerprint of the local gap closure when Weyl points form. By contrast, we find that the electron dynamics of the related compound

Temperature dependent non-monotonic bands shift in ZrTe5

\mathrm{WTe_2}

Probing band parity inversion in the topological insulator GeBi 2 Te 4 by linear dichroism in ARPES

is slower and temperature-independent, consistent with a topologically trivial nature of this material. Our results shows that tr-ARPES is sensitive to the small modifications of the unoccupied band structure accompanying the structural and topological phase transition of