This paper reviews experimental evidence and the related theoretical background on exotic
phenomena arising from local quadrupolar degrees of freedom. Recent extensive studies on …

PrV 2 Al 20 is a rare example of a heavy-fermion system based on strong hybridization
between conduction electrons and nonmagnetic quadrupolar moments of the cubic Γ 3 …

Quantum materials with non-Kramers doublets are a fascinating venue to realize multipolar
hidden orders. Impurity probes which break point group symmetries, such as implanted …

This review summarizes the synthetic aspects, the structural and crystal chemical
peculiarities as well as the physical properties of the members of the CeCr2Al20 type family …

We report time-of-flight neutron spectroscopy and neutron and x-ray diffraction studies of the
5 d 2 double perovskite magnets, Ba 2 M OsO 6 (M= Zn, Mg, Ca). These materials host …

Motivated by experimental and theoretical interest in realizing multipolar orders in d-orbital
materials, we discuss the quantum magnetism of J= 2 ions which can be realized in spin …

We study the Kondo lattice model of multipolar magnetic moments interacting with
conduction electrons on a triangular lattice. Bond-dependent electron hop**s induce a …

Orbital degrees of freedom in condensed matter could play important roles in forming a
variety of exotic electronic states by interacting with conduction electrons. In 4 f-electron …

Ferroquadrupole order associated with local 4 f atomic orbitals of rare-earth ions is a
realization of electronic nematic order. However, there are relatively few examples of …

Broken symmetries in solids involving higher order multipolar degrees of freedom are
historically referred to as “hidden orders” due to the formidable task of detecting them with …