Related papers: Ring Exchange and Correlated Fermions
Earlier theoretical results on $p$-$d$ and $d$-$d$ exchange interactions for zinc-blende semiconductors with $\mathrm{Cr}^{2{+}}$ and $\mathrm{Mn}^{3{+}}$ ions are revisited and extended by including contributions beyond the dominating…
Evidence is summarized attesting that the standard exchange field theory of ferromagnetism by Heisenberg has not been successful. It is replaced by the crystal field and a simple assumption that spin orientation is inexorably associated…
Triple quantum dots (TQDs) are promising semiconductor spin qubits because of their all-electrical control via fast, tunable exchange interactions and immunity to global magnetic fluctuations. These qubits can experience strong transverse…
Spin dynamics is calculated in the ferromagnetic (FM) state of the generalized Kondo lattice model taking into account strong on-site correlations between e_g electrons and antiferromagnetic (AFM) exchange among t_{2g} spins. Our study…
A new method of computing multipolar exchange interaction in spin-orbit coupled systems is developed using multipolar tensor expansion of the density matrix in LDA+U electronic structure calculation. Within mean-field approximation,…
Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes…
In high energy and condensed matter physics, particle exchange plays an essential role in the understanding of long-range interactions. For example, the exchange of massive bosons leads to the Yukawa potential. Phonon exchange between…
Spin correlations in the paramagnetic phase of lanthanum cuprate have been studied using polarized neutron scattering, with two important results. First, the temperature dependence of the characteristic energy scale of the fluctuations and…
This article gives a comprehensive review on the recent studies of the double exchange systems using non-perturbative approaches; the dynamical mean-field theory and the Monte Carlo method. Investigations beyond mean-field type treatments…
The theory of electron-phonon interaction in the presence of strong correlation has been investigated in the present work. Due to the so called spin-charge separation, it is argued that the electron-phonon interaction in the strongly…
Doping change and distortion effect on the double-exchange ferromagnetism are studied within a simplified double-exchange model. The presence of distortion is modelled by introducing the Falicov-Kimball interaction between itinerant…
We study the S=1/2 Heisenberg antiferromagnet on a square lattice with nearest-neighbor and plaquette four-spin exchanges (introduced by A.W. Sandvik, Phys. Rev. Lett. {\bf 98}, 227202 (2007).) This model undergoes a quantum phase…
We investigate the role of four-spin interactions in stabilizing exotic multiple-$Q$ topological spin textures and demonstrate their ability to realize a skyrmion crystal. While such higher-order interactions are known to be important,…
The theory of exchange symmetry of spin ordered states is extended to the case of high magnetic field. Low frequency spin dynamics equation for quasi-goldstone mode is derived for two cases of collinear and noncollinear antiferromagnets.
We calculate Heisenberg-type magnetic exchange interactions for SrMnO$_3$ under isotropic volume expansion using an approach that is based on total energy variations due to infinitesimal spin rotations around a given reference state. Our…
Theoretical ideas and experimental results concerning high temperature superconductors are reviewed. Special emphasis is given to calculations carried out with the help of computers applied to models of strongly correlated electrons…
We study triangular lattice spin-1/2 system with antiferromagnetic Heisenberg and ring exchanges using variational approach focusing on possible realization of spin liquid states. Trial spin liquid wave functions are obtained by Gutzwiller…
Motivated by recent discussion on possible quantum critical behavior in the coupled Cu-tetrahedra system Cu2Te2O5Br2, we present a comparative ab initio study of the electronic properties of Cu2Te2O5Br2 and the isostructural Cu2Te2O5Cl2. A…
Strongly interacting particles in one dimension subject to external confinement have become a topic of considerable interest due to recent experimental advances and the development of new theoretical methods to attack such systems. In the…
Photoirradiation effects in correlated electrons coupled with localized spins are studied based on the extended double-exchange model. In particular, we examine melting of an antiferromagnetic (AFM) charge order insulating state by varying…