Since the first demonstration of the generation of attosecond pulses (1 as= 10− 18 s) in the
extreme-ultraviolet spectral region, several measurement techniques have been introduced …

This Colloquium reviews the 25 year quest to understand the continuous (second-order),
mean-field-like phase transition occurring at 17.5 K in URu 2 Si 2. About ten years ago, the …

Spin-triplet superconductors are of extensive current interest because they can host
topological state and Majorana fermions important for quantum computation. The uranium …

Time-and angle-resolved photoemission spectroscopy (trARPES) using femtosecond
extreme ultraviolet high harmonics has recently emerged as a powerful tool for investigating …

Throughout the past three decades, the hidden order (HO) problem in URu2Si2 has
remained a 'hot topic'in the physics of strongly correlated electron systems with well over …

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 …

Time-resolved hard x-ray photoelectron spectroscopy (trHAXPES) is established using the x-
ray free-electron laser SACLA. The technique extends time-resolved photoemission into the …

We report angle-resolved photoemission spectroscopy experiments probing deep into the
hidden-order state of URu 2 Si 2, utilizing tunable photon energies with sufficient energy and …

Recent remarkable progress in angle-resolved photoelectron spectroscopy (ARPES) has
enabled the direct observation of the band structures of 4f and 5f materials. In particular …

We analyze a type of phase transition that appears in the spin-rotationally invariant form of
the underscreened Anderson lattice model and we obtain, with decreasing temperature, a …