Related papers: Electronic band structure and exchange coupling co…
Motivated by Sr2RuO4 the magnetic properties of edge states in a two-band spin-triplet superconductor with electron- and hole-like Fermi surfaces are investigated assuming chiral p-wave pairing symmetry. The two bands correspond to the…
Strongly interacting one-dimensional fermions form an effective spin chain in the absence of an external lattice potential. We show that the exchange coefficients of such a chain may be locally tuned by properly tailoring the transversal…
We have investigated the structural and magnetic transitions in CsCoO$_2$ using calorimetric measurements, neutron powder diffraction (NPD), density functional theory (DFT) calculations and muon-spin relaxation ($\mu$SR) measurements.…
The magnetic excitations of the square-lattice spin-1/2 antiferromagnet and high-Tc parent La2CuO4 are determined using high-resolution inelastic neutron scattering. Sharp spin waves with absolute intensities in agreement with theory…
In this article, we study the one dimensional Heisenberg spin-1/2 alternating bond chain in which the nearest neighbor exchange couplings are ferromagnetic (FM) and antiferromagnetic (AF) alternatively. By using exact diagonalization and…
We extracted, from strongly-correlated ab-initio calculations, a complete model for the chain subsystem of the $Sr_{0.4}Ca_{13.6}Cu_{24}O_{41}$ incommensurate compound. A second neighbor $t-J+V$ model has been determined as a function of…
We have employed first principles calculations to study the electronic structure and magnetic properties of the low-dimensional phosphates, Ba2Cu(PO4)2 and Sr2Cu(PO4)2. Using the self-consistent tight-binding lin- earized muffin-tin orbital…
We present an exhaustive study of Andreev crystals (ACs) -- quasi-one-dimensional superconducting wires with a periodic distribution of magnetic regions. The exchange field in these regions is assumed to be much smaller than the Fermi…
The minimal model to describe many spin chain materials with ferroelectric properties is the Heisenberg model with ferromagnetic nearest neighbor coupling J1 and antiferromagnetic next-nearest neighbor coupling J2. Here we study the…
We report the crystal structure, magnetization measurements, and band-structure calculations for the spin-1/2 quantum magnet CaCu2(SeO3)2Cl2. The magnetic behavior of this compound is well reproduced by a uniform spin-1/2 chain model with…
We present results of density-functional calculations on the magnetic properties of Cr, Mn, Fe and Co nano-clusters (1 to 9 atoms large) supported on Cu(001) and Cu(111). The inter-atomic exchange coupling is found to depend on competing…
We consider a long quantum wire at low electron densities. In this strong interaction regime a Wigner crystal may form, in which electrons comprise an antiferromagnetic Heisenberg spin chain. The coupling constant J is exponentially small,…
Employing first-principles electronic structure calculations in conjunction with the frozen-magnon method we study the effective exchange interactions and spin waves in local moment ferromagnets. As prototypes we have chosen three…
We determine the spin wave exchange stiffness $D$ and the exchange constant $A$ for the full Heusler compound \CFS using Brillouin light scattering spectroscopy. We find an extraordinarily large value of $D=715\pm20$ meV \AA$^2$…
Spin-orbit coupling has been conjectured to play a key role in the low-energy electronic structure of Sr2RuO4. Using circularly polarized light combined with spin- and angle-resolved photoemission spectroscopy, we directly measure the value…
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…
We present a study of the nearest--neighbor (nn) and next-nearest-neighbor (nnn) exchange constants between magnetic Cu centers of the spin-Peierls material CuGeO3. The dependence of these constants on the lattice parameters (modified e.g.…
KO2 exhibits concomitant antiferromagnetic (AFM) and structural transitions, both of which originate from the open-shell 2p electrons of O$_{2}^{-}$ molecules. The structural transition is accompanied by the coherent tilting of O$_{2}^{-}$…
We clarify the macroscopic symmetry and microscopic model-parameter conditions for emergence of spin-split electronic band structure in collinear antiferromagnets without atomic spin-orbit coupling. By using the microscopic multipole…
Neutron and X-ray diffraction, magnetic susceptibility, and specific heat measurements have been used to investigate the magnetic and structural phase transitions of the spinel system Fe1+xCr2-xO4(0.0<=x<=1.0). The temperature versus Fe…