Related papers: Jahn-Teller effect in systems with strong on-site …
The consequences of the Jahn-Teller (JT) orbital-lattice coupling for magnetism of pseudospin J_{eff}=1/2 and J_{eff}=0 compounds are addressed. In the former case, represented by Sr_2IrO_4, this coupling generates, through the so-called…
Exotic quantum phases, arising from a complex interplay of charge, spin, lattice and orbital degrees of freedom, are of immense interest to a wide research community. A well-known example of such an entangled behavior is the Jahn-Teller…
The Jahn-Teller effect is one of the most fundamental phenomena important not only for physics, but also for chemistry and material science. Solving the Jahn-Teller problem and taking into account strong electron correlations we show that…
Dynamical Jahn-Teller (DJT) effect in a spin-orbital coupled system on a honeycomb lattice is examined, motivated from recently observed spin-liquid behavior in Ba$_3$CuSb$_2$O$_9$. An effective vibronic Hamiltonian, where the superexchange…
We study an interplay between the orbital degeneracy and spin-orbit coupling giving rise to spin-orbital entangled states. As a specific example, we analyze the interaction of electrons occupying triply degenerate single-ion $t_{2g}$ levels…
This paper reviews recent experimental and theoretical developments of the dynamic Jahn-Teller effect-driven phenomena in heavy transition metal-based spin-orbit Mott insulators. In cubic $4d/5d$ transition metal compounds, the spin,…
The $5d^1$ ordered double perovskites present an exotic playground for studying novel multi-polar physics due to large spin-orbit coupling. We present Re L3 edge resonant inelastic X-ray scattering (RIXS) results that reveal the presence of…
Ultrasound velocity measurements of cubic spinel GeCo$_2$O$_4$ in single crystal were performed for the investigation of shear and compression moduli. The shear moduli in the paramagnetic state reveal an absence of Jahn-Teller activity…
Jahn-Teller (JT) electron-phonon coupling effects in the colossal magnetoresistance perovskite compounds $La_{1-x}A_xMnO_3$ are investigated. Electron-electron correlations between two degenerate Mn $e_g$ orbitals are studied in the…
We study the effects of magnetoelastic coupling on the degenerate ground state of the spin-1/2 antiferromagnetic Heisenberg model for the regular triangular spin cluster. Static displacement of spins spontaneously lifts the degeneracy of…
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…
Polarons and spin-orbit (SO) coupling are distinct quantum effects that play a critical role in charge transport and spin-orbitronics. Polarons originate from strong electron-phonon interaction and are ubiquitous in polarizable materials…
The properties of transition metal compounds are largely determined by nontrivial interplay of different degrees of freedom: charge, spin, lattice, but also orbital ones. Especially rich and interesting effects occur in systems with orbital…
In contrary to customarily consideration of the Jahn-Teller theorem for 3d-ion compounds in the orbital space only we point out that it has to be considered in the spin-orbital space. It is despite the weakness of the intraatomic spin-orbit…
It is shown that the d8 electron system occurring in the Ni2+ ion can have the non-magnetic ground state in the atomic scale formed by the Jahn-Teller effect. The tetragonal/trigonal off-cubic lattice distortion for the octahedral site…
The half-filled $t_{2g}$ shell of the $t_{2g}^3$ configuration usually, in LS coupling, hosts a S = 3/2 ground state with quenched orbital moment. This state is not Jahn-Teller active. Sufficiently large spin-orbit coupling $\zeta$ has been…
We investigate the effect of the experimentally observed Jahn-Teller distortion of the oxygen octahedra in LaTiO3 on the magnetic exchange. We present a localized model for the effective hopping between nearest-neighbor Ti ions and the…
We discuss phenomena arising from the combined influence of electron correlation and spin-orbit coupling, with an emphasis on emergent quantum phases and transitions in heavy transition metal compounds with 4d and 5d elements. A common…
It is shown that the layered antiferromagnetic order in stoechiometric LaMnO_3 cannot be understood purely from electronic interactions. On the contrary, it mainly results from strong cooperative Jahn-Teller deformations. Those involve a…
The ground-state properties of the spin-1 antiferromagnetic Heisenberg model on the corner-sharing tetrahedra, pyrochlore lattice, is investigated. By breaking up each spin into a pair of 1/2-spins, the problem is reduced to the equivalent…