Related papers: Low lying excitations of the Dynamical Jahn-Teller…
Dynamical Jahn-Teller effect has escaped so far direct observation in metallic systems. It is particularly believed to be quenched also in correlated conductors with orbitally degenerate sites such as cubic fullerides. Here the Gutzwiller…
Reduction factors (RF), that are needed when modeling vibronic systems by an effective Hamiltonian in an electronic basis, are calculated for the T_1u x h_g Jahn-Teller (JT) system. The results obtained will be useful when modeling the…
We review the recent theoretical treatment of fullerenes as pi-conjugated systems. Polaronic properties due to the Jahn-Teller type effects are mainly discussed. (1) A Su-Schrieffer-Heeger type electron-phonon model is applied to…
We propose variational states for the ground state and the low-energy collective rotator excitations in negatively charged C60N- ions (N=1...5). The approach includes the linear electron-phonon coupling and the Coulomb interaction on the…
A recent Letter reports photoemission data for the free C60 molecule, showing an interesting three-peak structure, presented as evidence of dynamic Jahn-Teller (DJT) effect in the C60+ ion. Those data constitute, along with earlier spectra…
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 apolar fullerenes C60 and C70 are not accessible for radio astronomy. Upon ionization static Jahn-Teller effects occur in C70+ that distort the D5h neutral symmetry to Cs. This point group is polar thus ionization induces a permanent…
We find the exact semiclassical (strong coupling) zero-point energy shifts applicable to the $e\otimes (n E)$ and $t\otimes (n H)$ dynamic Jahn-Teller problems, for an arbitrary number $n$ of discrete vibrational modes simultaneously…
We report results on ab initio calculations of excited states of the fullerene molecule by using configuration interaction (CI) approach with singly excited determinants (SCI). We have used both the experimental geometry and the one…
The electron-phonon interaction in $C_{70}$ anions is studied by making use of a lattice relaxation approach. We find there exists a Jahn-Teller effect in $C_{70}^{3-}$ system, due to an extra electron being doped to the double degenerate…
A simple, yet accurate solution of the electron-phonon coupling problem in C_{60} is presented. The basic idea behind it is to be found in the parametrization of the ground state electronic density of the system calculated making use of…
We investigate the occurrence of Hund's rule magnetism in C60(n+-) molecular ions, by computing the ground-state spin for all charge states n from -3 to +5. The two competing interactions, electron-vibration (e-v, including Jahn Teller,…
Orbital-lattice coupled excitation dynamics in orbitally degenerate correlated systems are examined. We present a theoretical framework, where both local vibronic excitations and superexchange-type inter-site interactions are dealt with on…
In a two orbital double exchange model we formulate Jahn-Teller coupled charge density wave in one electron per lattice site limit. Softening of Jahn-Teller phonons corresponding to distortion modes $Q_2$ or $Q_3$ associated with perfect…
We introduce an effective model for $e_g$ electrons to describe quasi-two-dimensional layered La$_{2-x}$Sr$_{x}$NiO$_4$ nickelates and study it using correlated wave functions on $8 \times 8 $ and $6 \times 6 $ clusters. The effective…
The pi electrons of isolated fullerene anions C60^{n-} (n betwen 1 and 6) are a quite unique finite system of electrons with an attractive interaction due to exchange of intramolecular phonons. This interaction may overwhelm Hund's rule and…
Considering C$_{60}$ as a model system for describing field emission from the extremity of a carbon nanotip, we explore electron emission from this fullerene excited by an intense, near-infrared, few-cycle laser pulse…
We report the temperature dependent mid- and near-infrared spectra of K4C60, Rb4C60 and Cs4C60. The splitting of the vibrational and electronic transitions indicates a molecular symmetry change of C604- which brings the fulleride anion from…
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…
We present the fingerprints of dynamic Jahn-Teller effect in resonant inelastic x-ray scattering (RIXS) spectra of K$_2$RuCl$_6$. We determined the dynamic Jahn-Teller model Hamiltonian of an embedded Ru$^{4+}$ ion using post Hartree-Fock…