Related papers: Jahn-Teller Coupled Charge Density Wave in A Two O…
We realize and study the ionic Hubbard model using an interacting two-component gas of fermionic atoms loaded into an optical lattice. The bipartite lattice has honeycomb geometry with a staggered energy-offset that explicitly breaks the…
The Hubbard model on the kagome lattice is presently often considered as a minimal model to describe the rich low-temperature behavior of AV$_{3}$Sb$_{5}$ compounds (with A=K, Rb, Cs), including charge-density waves (CDWs),…
We report evidence that the metallic phase in high Tc cuprate superconductors results from an instability of the quasi 2D-electron gas at densities lower or larger than the critical density for the formation of a Wigner polaronic crystal.…
With the use of the band structure calculations we demonstrate that previously reported [Nat. Materials {\bf 3}, 48 (2004)] experimental crystal and magnetic structures for NaMn$_7$O$_{12}$ are inconsistent with each other. The optimization…
The electron-phonon coupling strength in single-wall carbon nanotube (SWNT) bundles has been studied directly in the time-domain by femtosecond time-resolved photoelectron spectroscopy. We have measured the dependence of H(T_e,T_l), the…
Diffraction measurements performed via transmission electron microscopy and high resolution X-ray scattering reveal two distinct charge density wave transitions in Gd$_2$Te$_5$ at $T_{c1}$ = 410(3) and $T_{c2}$ = 532(3) K, associated with…
By an idealized quantum mechanical model, we formally describe the dispersion of nonretarded electromagnetic waves that express charge density oscillations near a fixed plane in three spatial dimensions (3D) at zero temperature. Our goal is…
Due to the interplay between charge fluctuation and geometry frustration, the doped kagome-lattice Mott insulator is a fascinating platform to realize exotic quantum states. Through the state-of-the-art density matrix renormalization group…
We discuss the nature of the different ground states of the half-filled Holstein model of spinless fermions in 1D. In the metallic regime we determine the renormalised effective coupling constant and the velocity of the charge excitations…
The Hubbard model has been employed successfully to understand many aspects of correlation driven physical properties, in particular, the magnetic order in itenerant electron systems. In some systems such as Heusler alloys, manganites etc.,…
The spin and charge excitations of the t--J ladder are studied by exact diagonalization techniques for several electron densities. The various modes are classified according to their spin (singlet or triplet excitations) and their parity…
The interplay between the electron repulsion $U$ and the Jahn-Teller electron-phonon interation $E_{LR}$ is studied with a large $d$ model for the ferromagnetic state of the manganese oxides. These two interactions collaborate to induce the…
I present the results of first principles calculations of the phonon dispersions and electron-phonon coupling for BaTi$_2$Sb$_2$O. The phonon dispersions show a weak lattice instability near the zone corners that leads to a charge-density…
A theoretical model is proposed for the (0,0,1) superlattice manganite system (LaMnO$_3$)$_n$(SrMnO$_3$)$_m$. The model includes the electron-electron, electron-phonon, and cooperative Jahn-Teller interactions. It is solved using a version…
A linear spin wave analysis of dimerization of alternating Heisenberg system with spins $s_{1}$ and $s_{2}$ on linear chain as well as square lattice is presented. Among the several possible dimerized configurations considered in two…
Chaotic lattice models at high temperature are generically expected to exhibit diffusive transport of all local conserved charges. Such diffusive transport is usually associated with overdamped relaxation of the associated currents. Here we…
We present a constrained density functional perturbation theory scheme for the calculation of structural and harmonic vibrational properties of insulators in the presence of an excited and thermalized electron-hole plasma. The method is…
In 1937 the Jahn-Teller (JT) effect addressed the instability (potential or actual) of non-linear symmetric molecules with degenerate orbital electronic states. In view of the large variety of JT activity that has taken place since then, we…
We report on electronic collective excitations in RMn2O5 (R= Pr, Sm, Gd, Tb) showing condensation starting at and below TN\simTC\sim40-50 K. Its origin is understood as partial delocalized eg electron orbitals in the Jahn-Teller distortion…
The infinite-$U$ Anderson model coupled to a Jahn-Teller phonon is studied using the slave boson method on the basis of the large degeneracy expansion (1/N) scheme. The model Hamiltonian acts on the orbital degrees of freedom. The main…