Related papers: Orthorhombic fulleride (CH3NH2)K3C60 close to Mott…
Within dynamical mean-field theory, we study the metal-insulator transition of a twofold orbitally degenerate Hubbard model as a function of a splitting \Delta of the degeneracy. The phase diagram in the U-\Delta plane exhibits two-band and…
We review some theoretical aspects connected with the interplay of strong electron correlations and vibron phenomena in negative fullerene ions and in solid fulleride conductors, superconductors and insulators. The first part covers…
Fullerene solids doped with alkali metals (A$_3$C$_{60}$, A = K, Rb, Cs) exhibit a superconducting transition temperature ($T_c$) as high as 40 K, and their unconventional superconducting properties have been a subject of debate. With…
Microwave study using cavity perturbation technique revealed that the conductivity of antiferromagnet (NH$_3$)K$_{3-x}$Rb$_x$C$_{60}$ at 200K is already 3-4 orders of magnitude smaller than those of superconductors, K$_3$C$_{60}$ and…
Motivated by the recent experimental report of a possible light-induced superconductivity in A3C60 at high temperature [Mitrano et al., Nature 530, 451 (2016)], we investigate theoretical mechanisms for enhanced superconductivity in A3C60…
Alkali-doped fullerides A$_n$C$_{60}$ show a remarkably wide range of electronic phases in function of A= Li, Na, K, Rb, Cs and the degree of doping, $n=1-5$. While the presence of strong electron correlations is well established, recent…
The alkali-doped fullerides A$_3$C$_{60}$ are half-filled three-orbital Hubbard systems which exhibit an unconventional superconducting phase next to a Mott insulator. While the pairing is understood to arise from an effectively negative…
The exchange interactions and magnetic structure in layered system CuMnO2 (mineral crednerite) and in nonstoichiometric system Cu1.04Mn0.96O2, with triangular layers distorted due to orbital ordering of the Mn3+ ions, are studied by…
Alkali-doped fullerides A3C60 (A=K, Rb, Cs) are surprising materials where conventional phonon-mediated superconductivity and unconventional Mott physics meet, leading to a remarkable phase diagram as a function of the volume per C60…
Cs$_3$C$_{60}$ in the A15 structure is an antiferromagnet at ambient pressure in contrast with other superconducting trivalent fullerides. Superconductivity is recovered under pressure and reaches the highest critical temperature of the…
In the orthorhombic manganites o-RMnO3, where R is a heavy rare earth (R = Gd-Yb), the Mn3+ sublattice is known to undergo two magnetic transitions. The low temperature phase has an antiferromagnetic structure (collinear or elliptical),…
The trivalent alkali fullerides A$_3$C$_{60}$, where C$_{60}$ are a well established family of molecular superconductors. The electron pairing has s-wave symmetry and is due to standard electron-phonon coupling, in particular by Jahn-Teller…
Evidence for multiple magnetic transitions and unconventional spin exchange interactions in the ilmenite insulator MnTiO3 is provided via neutron scattering. On cooling, while G-type antiferromagnetic (AFM) order sets in first at 63 K with…
On the basis of density functional theory electronic band structure calculations using the augmented spherical wave method, the electronic and magnetic properties of the orthorhombic and tetragonal phases of Ca3Mn2O7 were investigated and…
Over the past 20 years, fullerides have been studied as the source of high-transition-temperature (Tc) superconductivity except for copper oxides. The recent finding of the Mott insulating state right beside superconductivity in Cs3C60 has…
The discovery in 1991 of high temperature superconductivity (SC) in A3C60 compounds, where A is an alkali ion, has been initially ascribed to a BCS mechanism, with a weak incidence of electron correlations. However various experimental…
Two-dimensional van der Waals compounds with magnetic ions on a honeycomb lattice are hosts to a variety of exotic behavior. The magnetic interactions in one such compound, MnPSe$_3$, are investigated with elastic and inelastic neutron…
Strong electron-electron interaction can induce Mott insulating state, which is believed to host unusual correlated phenomena such as quantum spin liquid when quantum fluctuation dominates and unconventional superconductivity through…
The phase diagram of half-doped manganite systems of formula A_{0.5}A'_{0.5}MnO_3 is investigated within a single-orbital model incorporating magnetic double-exchange and superexchange, together with intersite Coulomb and electron-lattice…
We investigate the formation of non-equilibrium superconducting states in driven alkali-doped fullerides A$_3$C$_{60}$. Within a minimal three-orbital model for the superconductivity of these materials, it was recently demonstrated…