Related papers: Ab Initio Calculation of Spin Gap Behavior in CaV4…
The magnon disp ersion in Ca2RuO4 has been determined by inelastic neutron scattering on single crytals containing 1% of Ti. The dispersion is well described by a conventional Heisenberg model suggesting a local moment model with nearest…
We study antiferromagnetic, $S=1/2$ Heisenberg models with nearest and second neighbor interactions on the one-fifth depleted square lattice which describes the spin degrees of freedom in the spin-gap system CaV$_4$O$_9$. The meta-plaquette…
The Heisenberg exchange interaction between neighboring quantum dots allows precise voltage control over spin dynamics, due to the ability to precisely control the overlap of orbital wavefunctions by gate electrodes. This allows the study…
We report on {\it ab initio} time-dependent spin dynamics simulations for a two-center magnetic molecular complex based on time-dependent non-collinear spin density functional theory. In particular, we discuss how the dynamical behavior of…
Kitaev interactions underlying a quantum spin liquid have been long sought, but experimental data from which their strengths can be determined directly is still lacking. Here, by carrying out inelastic neutron scattering measurements on…
Neutron diffraction, magnetization, resistivity, and heat capacity measurements on the 6H-perovskite Ba3BiRu2O9 reveal simultaneous magnetic and structural dimerization driven by strong magnetoelastic coupling. An isostructural but strongly…
Heisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for quantum information processing and simulation. Although so far unrealized, extended Heisenberg spin chains can enable…
We show that puzzling recent experimental results on spin diffusion in a strongly interacting atomic gas may be understood in terms of the predicted spin diffusion coefficient for a generic strongly interacting system. Three important…
We calculate the crystal-field splitting, ground-state Kramers doublet and intersite exchange interactions within the ground-state doublet manifold using an ab initio Hubbard-I based approach for a representative set of Ce and Yb…
The oxygen O2p_sigma and copper Cu4s and Cu3d_x^2-y^2 orbitals are involved in a simple LCAO model for determination of the conduction band and the oxygen-oxygen hopping is considered as a small parameter with respect to the transition…
An antiferromagnetic (AF) spin fluctuation induced pairing model is proposed for the electron-doped cuprate superconductors. It suggests that, similar to the hole-doped side, the superconducting gap function is monotonic d_{x^2-y^2}-wave…
A quantitative description of the exchange interaction in quantum dots is relevant for modeling gate operations of spin qubits. By measuring the amplitude and frequency of exchange-driven qubit state oscillations, we measure the detuning…
We study spin-1/2 Heisenberg antiferromagnets on a diamond-like-decorated square lattice perturbed by two kinds of further neighbor couplings. In our previous study [J. Phys. Soc. Jpn. 85, 094002 (2016)], the second-order effective…
Effects of possible orbital order in magnetic properties of two-dimensional spin gap system for CaV$_4$O$_9$ are investigated theoretically. After analyzing experimental data, we show that single orbital models assumed in the literature are…
We study the uniform magnetic susceptibility and spin-gap for recently proposed Heisenberg model Hamiltonians for CaV_4O_9 based on the orbital ordering scenario of Marini and Khomskii and the LDA calculations of Pickett. We argue that the…
We consider the spin-1/2 XXX chain weakly perturbed away from integrability by an isotropic next-to-nearest neighbor exchange interaction. Recently, it was conjectured that this model possesses an infinite tower of quasiconserved integrals…
We report a study of the anisotropic exchange interactions in bulk CrO_2 calculated from first principles within density functional theory. We determine the exchange coupling energies, using both the experimental lattice parameters and…
We measure singlet-triplet dephasing in a two-electron double quantum dot in the presence of an exchange interaction which can be electrically tuned from much smaller to much larger than the hyperfine energy. Saturation of dephasing and…
We present the results of band structure calculations for ACr2X4 (A=Zn, Cd, Hg and X=O, S, Se) spinels. Effective exchange coupling constants between Cr spins are determined by fitting the energy of spin spirals to a classical Heisenberg…
Many low dimensional spin systems with a dimerized or ladder-like antiferromagnetic exchange coupling have a gapped excitation spectrum with magnetic bound states within the spin gap. For spin ladders with an even number of legs the…