Publication Type
Journal
Journal Name
Physical Review B
Publication Date
Page Number
100501
Volume
87
Issue
10
Abstract
Spin dynamics in superconducting (Tl,Rb)2Fe4Se5 was investigated using the inelastic neutron
scattering technique. Spin wave branches that span an energy range from 6.5 to 209 meV are success-
fully described by a Heisenberg model whose dominant interactions include only the in-plane nearest
(J1 and J0
1) and next nearest neighbor (J2 and J0
2) exchange terms within and between the tetramer
spin blocks, respectively. These exchange constants, experimentally determined in this work, would
crucially constrain the diverse theoretical viewpoints on magnetism and superconductivity in the
Fe-based materials.
