Related papers: Magnetic transition and polaron crossover in a two…
The Hubbard-Holstein model is studied including double-exchange interaction and superexchange interaction using a variational phonon basis obtained through the modified Lang-Firsov (MLF) transformation followed by the squeezing…
Based on the combined model of the double exchange and the polaron, we have studied the small-to-large polaron crossover transition and explored its effects on the magnetic and transport properties in colossal magnetoresistance (CMR)…
The influence of the homogeneous magnetic field on a single mobile hole in a magnetic insulator, as represented by the two-dimensional t-J model, is investigated by considering the coupling of the field to the orbital current. The energy of…
Using the perturbation method based on a variational phonon basis obtained by the modified Lang-Firsov (MLF) transformation, the two-site single polaron Holstein model is studied in presence of a difference in bare site energies…
A crossover between two mechanisms destabilizing the magnetization in equilibrium by the spin transfer effect is found in a ferromagnetic multilayer consisting of an in-plane magnetized free layer and a perpendicularly magnetized pinned…
We investigate the bipolaronic crossover and the pairing transition for a two-orbital model with Jahn-Teller coupling to a two-fold degenerate phonon mode. The evolution from weak to strong coupling is reminiscent of the behavior of the…
In this work, we study the effects of a transverse magnetic field in a Kondo lattice model with two $f$ orbitals interacting with the conduction electrons. The $f$ electrons that are present on the same site interact through Hund's…
The transport properties of interacting electrons for which the spin degree of freedom is taken into account are numerically studied for small two dimensional diffusive clusters. On-site electron-electron interactions tend to delocalize the…
A treatment of many-electron polar and $s-d(f)$ exchange models is carried out in connection with the development of the theory of magnetism of transition and rare-earth metals, as well as their compounds. Particular emphasis is placed on…
The electron-electron correlations in a many-electron (Ne = 1, 2,..., 5) quantum dot confined by a parabolic potential is investigated in the presence of a single magnetic ion and a perpendicular magnetic field. We obtained the energy…
A field-induced crossover is observed in the resistivity and magnetization (M) of a La(0.7)Pb(0.3)MnO(3) single crystal. The field-dependence of the resistivity and M suggests that a small spin-canted species with mean-field-like…
Based on the spin-blockade model for organic magnetoresistance we present an analytic expression for the polaron-bipolaron transition rate, taking into account the effective nuclear fields on the sites. We reveal the physics producing…
Magneto-polaronic effects are considered in electron transport through a single-level vibrating quantum dot subjected to a transverse (to the current flow) magnetic field. It is shown that the effects are most pronounced in the regime of…
We study the impact of an external magnetic field on the long-range electron transport in quasi-one-dimensional materials, such as polypeptides, (semi-) conducting polymers and macromolecules, taking into account the electron-lattice…
Understanding the interplay between charge and spin and its effects on transport is a ubiquitous challenge in quantum many-body systems. In the Fermi-Hubbard model, this interplay is thought to give rise to magnetic polarons, whose dynamics…
The stacking of intrinsically magnetic van der Waals materials provides a fertile platform to explore tunable transport effects of magnons, presenting significant prospects for spintronic applications. The possibility of having…
We study ferromagnetic transition in three-dimensional double-exchange model. The influence of strong spin fluctuations on conduction electrons is described in coherent potential approximation. In the framework of thermodynamic approach we…
The structure of bound magnetic polarons in an antiferromagnetic matrix is studied in the framework of two-dimensional (2D) and three-dimensional (3D) Kondo-lattice models in the double exchange limit (J_H >> t). The conduction electron is…
A compact expression has been obtained for the superexchange coupling of magnetic ions via intermediate anions with regard to polaron effects at both magnetic ions and intermediate anions. This expression is used to analyze the main…
On the basis of the two-site polaron problem, which we solve by exact diagonalization, we analyse the spectral properties of polaronic systems in view of discerning localized from itinerant polarons and bound polaron pairs from an ensemble…