Temperature-dependent spin gap and singlet ground state inBaCuSi2O6

Y. Sasago, K. Uchinokura, A. Zheludev, G. Shirane
1997 Physical Review B (Condensed Matter)  
Bulk magnetic measurements and inelastic neutron scattering were used to investigate the spin-singlet ground state and magnetic gap excitations in BaCuSi2O6, a quasi-2-dimensional antiferromagnet with a bilayer structure. The results are well described by a model based on weakly interacting antiferromagnetic dimers. A strongly temperature-dependent dispersion in the gap modes was found. We suggest that the observed excitations are analogous to magneto-excitons in light rare-earth compounds, but
more » ... are an intrinsic property of a simple Heisenberg Hamiltonian for the S=1/2 magnetic bilayer.
doi:10.1103/physrevb.55.8357 fatcat:3fropaegqfhw5bjj3dq5g4kqoi