Li$_2$VO(Si,Ge)O$_4$, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet

R. Melzi; P. Carretta; A. Lascialfari; M. Mambrini; M. Troyer; P. Millet; F. Mila

doi:10.1103/PhysRevLett.85.1318

paper

Li $_{2}$ VO(Si,Ge)O $_{4}$ , a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet

arXiv:cond-mat/0005273 · doi:10.1103/PhysRevLett.85.1318

Abstract

NMR and magnetization measurements in Li $_{2}$ VOSiO $_{4}$ and Li $_{2}$ VOGeO $_{4}$ are reported. The analysis of the susceptibility shows that both compounds are two-dimensional $S = 1/2$ Heisenberg antiferromagnets on a square lattice with a sizeable frustration induced by the competition between the superexchange couplings $J_{1}$ along the sides of the square and $J_{2}$ along the diagonal. Li $_{2}$ VOSiO $_{4}$ undergoes a low-temperature phase transition to a collinear order, as theoretically predicted for $J_{2} / J_{1} > 0.5$ . Just above the magnetic transition the degeneracy between the two collinear ground states is lifted by the onset of a structural distortion.

4 pages, 4 figures

Li2​VO(Si,Ge)O4​, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet

Abstract

Li $_{2}$ VO(Si,Ge)O $_{4}$ , a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet