1.

Variational approach to the doped Shastry-Sutherland model for the description of SrCu_(2-x)Mg_x(BO_3)_2 system

Using variational algorithm on an infinite Shastry-Sutherland lattice, we show that the introduction of a single quenched magnetic vacancy into a singlet ground state leads to a formation of a small and extremely anisotropic spin polaron surrounding the vacancy site. The presence of such nonmagnetic impurity leads to a formation of new in-gap peaks in the dynamical spin structure factor. Theoretical calculations are shown to qualitatively account for high resolution neutron scattering measurements on a single crystal SrCu_(2-x)Mg_x(BO_3)_2 with x~0.05.

B.03 Paper at an international scientific conference

COBISS.SI-ID: 21415463

2.

Spin Hamiltonian of the triangular layered alpha-NaMnO_2 system

We investigated the ESR measurements performed on alpha-NaMnO_2 polycrystalline sample, a quantum spin-2 system on a frustrated 2D triangular lattice with spatially anisotropic Heisenberg exchange. From the susceptibility curve, we determined the nearest-neighbor antiferromagnetic exchange coupling constants by employing the finite-temperature Lanczos method. The dominant magnetic anisotropy term of the single-ion type was evaluated from the ESR linewidth.

B.03 Paper at an international scientific conference

COBISS.SI-ID: 22254631

3.

Long-range magnetic order in the spin-1/2 Kagome antiferromagnet in presence of Dzyaloshinsky-Moriya interactions

We studied the consequences of Dzyaloshinsky-Moriya interactions on the spin-spin correlations in the S=1/2 Heisenberg model on the Kagome lattice. We found that out-of-plane Dz/J>0.1 component spontaneously breaks the U(1) symmetry and stabilizes the coplanar configurations of the spins. Application to the ZnCu_3(OH)_6Cl_2 compound was discussed.

B.03 Paper at an international scientific conference

COBISS.SI-ID: 22254887