We have performed time-of-flight neutron scattering measurements on powder samples of the unconventional spin-Peierls compound TiOBr using the fine-resolution Fermi chopper spectrometer (SEQUOIA) at the SNS. These measurements reveal two branches of magnetic excitations within the commensurate and incommensurate spin-Peierls phases, which we associate with n = 1 and n = 2 triplet excitations out of the singlet ground state. These measurements represent the first direct measure of the singlet-triplet energy gap in TiOBr, which is determined to be Eg = 21.2 +/- 1.0 meV.
@article{arxiv.1009.4185,
title = {Singlet-Triplet Excitations in the Unconventional Spin-Peierls System TiOBr},
author = {J. P. Clancy and B. D. Gaulin and C. P. Adams and G. E. Granroth and A. I. Kolesnikov and T. E. Sherline and F. C. Chou},
journal= {arXiv preprint arXiv:1009.4185},
year = {2016}
}