paper

Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTe $_{2}$ O $_{6}$

arXiv:2107.05331 · doi:10.1103/PhysRevB.104.144402

Abstract

The magnetic Hamiltonian of the Heisenberg quantum antiferromagnet SrCuTe $_{2}$ O $_{6}$ is studied by inelastic neutron scattering technique on powder and single crystalline samples above and below the magnetic transition temperatures at 8 K and 2 K. The high temperature spectra reveal a characteristic diffuse scattering corresponding to a multi-spinon continuum confirming the dominant quantum spin-chain behavior due to the third neighbour interaction J $_{in t r a}$ = 4.22 meV (49 K). The low temperature spectra exhibits sharper excitations at energies below 1.25 meV which can be explained by considering a combination of weak antiferromagnetic first nearest neighbour interchain coupling J $_{1}$ = 0.17 meV (1.9 K) and even weaker ferromagnetic second nearest neighbour J $_{2}$ = -0.037 meV (-0.4 K) or a weak ferromagnetic J $_{2}$ = -0.11 meV (-1.3 K) and antiferromagnetic J $_{6}$ = 0.16 meV (1.85 K) giving rise to the long-range magnetic order and spin-wave excitations at low energies. These results suggest that SrCuTe $_{2}$ O $_{6}$ is a highly one-dimensional Heisenberg system with three mutually perpendicular spin-chains coupled by a weak ferromagnetic J $_{2}$ in addition to the antiferromagnetic J $_{1}$ or J $_{6}$ presenting a contrasting scenario from the highly frustrated hyper-hyperkagome lattice (equally strong antiferromagnetic J $_{1}$ and J $_{2}$ ) found in the iso-structural PbCuTe $_{2}$ O $_{6}$ .

9 pages, 5+2 figures

Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTe2​O6​

Abstract

Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTe $_{2}$ O $_{6}$