Related papers: Enhanced ferromagnetism from electron-electron int…
We investigate the magnetic properties of spin-$1/2$ charged Fermi gases with ferromagnetic coupling via mean-field theory, and find the interplay among the paramagnetism, diamagnetism and ferromagnetism. Paramagnetism and diamagnetism…
The magnon exchange mechanism of ferromagnetic superconductivity (FM-superconductivity) was developed to explain in a natural way the fact that the superconductivity in $UGe_2$, $ZrZn_2$ and $URhGe$ is confined to the ferromagnetic…
Being motivated by the surge of fermionic quantum Monte Carlo simulations at finite temperature, we present a detailed analysis of the permutation-cycle properties of path integral Monte Carlo (PIMC) simulations of degenerate electrons.…
The emergence of ferro- and ferrimagnetic behavior in insulating materials is uncommon, largely due to Hund's rules. Utilizing symmetry analysis, first-principles methods, and classical Monte Carlo simulations, \textcolor{black}{we report…
Tight-binding Hamiltonians with single and multiple orbitals exhibit an intriguing array of magnetic phase transitions. In most cases the spin ordered phases are insulating, while the disordered phases may be either metallic or insulating.…
We study formation and screening of local magnetic moments in the two-band Hubbard model in the presence of Hund exchange interaction using dynamic mean field theory approach. The characteristic temperatures of the formation, beginning and…
Several prominent proposals have suggested that spins of localized electrons could serve as quantum computer qubits. The exchange interaction has been invoked as a means of implementing two qubit gates. In this paper, we analyze the…
An unusual increase of the conductance with temperature is observed in clean quantum point contacts for conductances larger than 2e^2/h. At the same time a positive magnetoresistance arises at high temperatures. A model accounting for…
We present a Monte Carlo study of the finite temperature properties of an extended Hubbard-Peierls model describing one dimensional $\pi$-conjugated polymers. The model incorporates electron-phonon and hyperfine interaction and it is solved…
We evaluate the effective interactions in a fluid of electrons moving in a plane, on the approach to the quantum phase transition from the paramagnetic to the fully spin-polarized phase that has been reported from Quantum Monte Carlo runs.…
We theoretically study dynamic properties of thin ferromagnetic films in contact with normal metals. Moving magnetizations cause a flow of spins into adjacent conductors, which relax by spin flip, scatter back into the ferromagnet, or are…
One year after their initial discovery, two schools of thought have crystallized regarding the electronic structure and magnetic properties of ferropnictide systems. One postulates that these are itinerant weakly correlated metallic systems…
Microscopic models of classical degrees of freedom coupled to non-interacting fermions occur in many different contexts. Prominent examples from solid state physics are descriptions of colossal magnetoresistance manganites and diluted…
The description of interacting many-electron systems in external magnetic fields is considered in the framework of the optimized effective potential method extended to current-spin-density functional theory. As a case study, a…
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…
The Quantum Monte Carlo method for spin 1/2 fermions at finite temperature is formulated for dilute systems with an s-wave interaction. The motivation and the formalism are discussed along with descriptions of the algorithm and various…
We investigate the two-orbital periodic Anderson model, where the local orbital fluctuations of f-electrons couple with a two-fold degenerate Jahn-Teller phonon, by using the dynamical mean-field theory. It is found that the heavy fermion…
We have used Monte Carlo simulation techniques to obtain the magnetic phase diagram of the double exchange Hamiltonian. We have found that the Berry's phase of the hopping amplitude has a negligible effect in the value of the magnetic…
In response to the experimental discovery of double perovskite Ru- base material, The magnetic and electronic properties of the double exchange mechanism are studied theoretically. The electron band structure and the spin wave spectrum…
The behavior of the compensation temperature of a mixed Ising ferrimagnetic system on a square lattice in which the two interpenetrating square sublattices have spins $\sigma$ ($\pm 1/2$) and spins $S$ ($\pm 1,0$) has been studied with…