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 …

This topical review describes the multitude of unconventional behaviors in the hidden order,
heavy fermion, antiferromagnetic and superconducting phases of the intermetallic …

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

Exotic electronic states resulting from entangled spin and orbital degrees of freedom are
hallmarks of strongly correlated f-electron systems. A spectacular example is the so-called …

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 …

Using inelastic X-ray scattering beyond the dipole limit and hard X-ray photoelectron
spectroscopy we establish the dual nature of the U 5 f electrons in UM 2 S i 2 (M= Pd, Ni, Ru …

The multipole concept, which characterizes the spacial distribution of scalar and vector
objects by their angular dependence, has already become widely used in various areas of …

Using high resolution tender x-ray resonant inelastic scattering and hard x-ray nonresonant
inelastic scattering beyond the dipole limit we were able to detect electronic excitations in …

The nature of the second-order phase transition that occurs in URu 2 Si 2 at 17.5 K remains
puzzling despite intensive research. A key question emerging in the field is whether a …

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 …