Ultrafast Angle-Resolved Photoemission Spectroscopy of Quantum Materials

Techniques in time- and angle-resolved photoemission spectroscopy have facilitated a number of recent advances in the study of quantum materials. We review developments in this field related to the study of incoherent nonequilibrium electron dynamics, the analysis of interactions between electrons and collective excitations, the exploration of dressed-state physics, and the illumination of unoccupied band structure. Future prospects are also discussed.Comment: 7 pages, 6 figure

The gap amplification at a "shape resonance" in a superlattice of quantum stripes: a mechanism for high Tc

The amplification of the superconducting critical temperature Tc from the low temperature range in homogeneous 2D planes (Tc<23 K) to the high temperature range (23 K<Tc<150 K) in an artificial heterostructure of quantum stripes is calculated. The high Tc is obtained by tuning the chemical potential near the bottom of the nth subband at a "shape resonance", in a range, whithin the energy cutoff for the pairing interaction. The resonance for the gap at the nth "shape resonance" is studied for a free electron gas in the BCS approximation as a function of the stripe width L, and of the number of electrons {\rho} per unit surface. An amplification factor for coupling 0.1<{\lambda}<0.3 is obtained at the third shape resonance raising the critical temperature in the high Tc range.Comment: 9 pages 6 figure

The impact of peoples' personal dispositions and personalities on their trust of robots in an emergency scenario

Humans should be able to trust that they can safely interact with their home companion robot. However, robots can exhibit occasional mechanical, programming or functional errors. We hypothesise that the severity of the consequences and the timing of a robot's different types of erroneous behaviours during an interaction may have different impacts on users' attitudes towards a domestic robot. First, we investigated human users' perceptions of the severity of various categories of potential errors that are likely to be exhibited by a domestic robot. Second, we used an interactive storyboard to evaluate participants' degree of trust in the robot after it performed tasks either correctly, or with 'small' or 'big' errors. Finally, we analysed the correlation between participants' responses regarding their personality, predisposition to trust other humans, their perceptions of robots, and their interaction with the robot. We conclude that there is correlation between the magnitude of an error performed by a robot and the corresponding loss of trust by the human towards the robot. Moreover we observed that some traits of participants' personalities (conscientiousness and agreeableness) and their disposition of trusting other humans (benevolence) significantly increased their tendency to trust a robot more during an emergency scenario.Peer reviewe