Neutron scattering from the static and dynamic lattice of SrCu2(BO3)2 in its Shastry-Sutherland singlet ground state

Elastic and inelastic neutron scattering results show that SrCu2(BO3)2 enters its low-temperature singlet ground state below 10 K without an obvious accompanying structural phase transition, despite suggestions emanating from earlier heat capacity measurements. However, evidence for significant spin-phonon coupling is found in the energy widths, and the corresponding lifetimes, of transverse acoustic phonons propagating in the (H00) direction …