We review recent progress in understanding the different spatial broken symmetries that
occur in the normal states of the family of charge-transfer solids (CTS) that exhibit …

After the revival of the magnetoelectric effect which took place in the early 2000s, the interest
in multiferroic materials displaying simultaneous presence of spontaneous long-range …

We present a study of the effects of simultaneous charge and spin frustration on the two-
dimensional strongly correlated quarter-filled band on an anisotropic triangular lattice. Our …

Bulk and surface electronic states of MgTi2O4 have been investigated by means of x-ray
absorption spectroscopy (XAS), hard x-ray photoemission spectroscopy (HAXPES), and …

We present a valence transition model for electron-and hole-doped cuprates, within which
there occurs a discrete jump in ionicity Cu 2+→ Cu 1+ in both families upon doping, at or …

A general mechanism by which orbital ordering, coupled to Peierls-like lattice distortions,
can induce an electronic switchable polarization is discussed within a model Hamiltonian …

We study an orbital compass model on a checkerboard lattice where orbital degree of
freedom is represented by the pseudospin operator. Competition arises from an Ising …

We add a Heisenberg interaction term∝ λ in the one-dimensional SU (2)⊗ XY spin-orbital
model introduced by Kumar. At λ= 0 the spin and orbital degrees of freedom can be …

The orbital compass model in a checkerboard lattice is studied. There is a competition
between the interaction for the z component of the orbital pseudo-spin along the …

Determination of the mechanism of correlated-electron superconductivity (SC) has turned
out to be the hardest problem in condensed matter physics. After nearly three decades of …