Related papers: Double-exchange via degenerate orbitals
The microscopic mechanism by which doped holes disrupt the antiferromagnetic order is one of the fundamental questions in cuprates. In this work, we propose a unified microscopic theory in which doped holes form spatially localized…
We show that an interplay of double exchange and impurity randomness can explain the competition between metal-ferromagnetic and insulating charge ordered states in doped manganites. The double exchange is simplified in the Ising type,…
We report on semiclassical angle-dependent magnetoresistance oscillations (AMRO) and the Shubnikov-de Haas effect in the electron-overdoped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_4$. Our data provide convincing evidence for magnetic…
The electron-doping-driven collapse of the charge gap and staggered magnetization of the spin-orbit-assisted Mott insulator Sr$_{3}$Ir$_{2}$O$_{7}$ is explored via first-principles computational methods. In the antiferromagnetic phase, the…
Using the constrained-path Monte Carlo method, a two-orbital model for the pnictide superconductors is studied at half filling and in both the electron- and hole-doped cases. At half filling, a stable $(\pi,0)$/$(0,\pi)$ magnetic order is…
We study the effects of electron doping in Mott insulators containing d^4 ions such as Ru4+, Os4+, Rh5+, and Ir5+ with J=0 singlet ground state. Depending on the strength of the spin-orbit coupling, the undoped systems are either…
The spin and orbital phase diagram for perovskite manganites are investigated as a function of temperature and hole concentration. The superexchange and double exchange interactions dominate the ferromagnetic phases in the low and high…
The exchange-degeneracy of the mesonic $f$, $\omega $, $\rho $ and $a_{2}$ Regge trajectories, dominant at moderate and high energies in hadron elastic scattering, is analyzed from two viewpoints. The first one concerns the masses of the…
Theory of dilution effect in orbital ordered system is presented. The $e_g$ orbital model without spin degree of freedom and the spin-orbital coupled model in a three-dimensional simple-cubic lattice are analyzed by the Monte-Carlo…
WTe$_2$ is a multifunctional quantum material exhibiting numerous emergent phases in which tuning of the carrier density plays an important role. Here we demonstrate two non-monotonic changes in the electronic structure of WTe$_2$ upon…
We present our theoretical results on an effective two-band double-exchange model on a pyrochlore lattice for understanding intricate phase competition in Mo pyrochlore oxides. The model includes the twofold degeneracy of $e_g'$ orbitals…
We propose a class of topological metals, which we dub \emph{Hund nodal line semimetals}, arising from the strong Coulomb interaction encoded in the Hund's coupling between itinerant electrons and localized spins. We here consider a…
Multiorbital Hubbard models with Hund coupling and crystal-field splitting exhibit an instability toward spin-triplet excitonic order in the parameter regime characterized by strong local spin fluctuations. Upon chemical doping, two…
Defects intentionally introduced into magnetic materials often have a profound effect on the physical properties. Specifically tailored neutron spectroscopic experiments can provide detailed information on both the local exchange…
The quantum-mechanical orbitals in carbon nanotubes are doubly degenerate over a large number of states in the Coulomb blockade regime. We argue that this experimental observation indicates that electrons are reflected without mode mixing…
Double exchange mechanism is believed to favor transport along ferromagnetic directions, the failure of which in explaining the unusual resistivity anisotropy in iron pnictides is investigated. Several factors intrinsic to the microscopic…
We study the two orbital double-exchange model in two dimensions in the presence of antiferromagnetic (AF) superexchange, strong Jahn-Teller coupling, and substitutional disorder. At hole doping x=0.5 we explore the `bicritical' regime…
Question about the appearance of different magnetic structures in the family of compounds La1-xCaxMnO3,is investigated theoretically. It is supposed that the whole series has GdFeO3 structure type. The problem is considered at absolute zero…
In this work, we study the electronic properties of monolayer transition metal dichalcogenide materials subjected to aliovalent doping, using Nb-doped WS2 as an exemplar. Scanning transmission electron microscopy imaging of the as-grown…
Due to the complex interplay of magnetic, structural, electronic, and orbital degrees of freedom, biaxial strain is known to play an essential role in the doped manganites. For coherently strained La(2/3)Ca(1/3)MnO(3) thin films grown on…