A prior report of the emergence of chirality for the (2x2x2) charge density wave (CDW) in TiSe2 has attracted much interest; the drastic symmetry breaking is highly unusual with few precedents [1]. In that study, key evidence was provided by x-ray diffraction measurements of two superlattice reflections, (1.5 1.5 0.5) and (2.5 1 0). The (2.5 1 0) reflection appeared to show an anomalously large intensity and a transition onset at ~7 K below that of the (1.5 1.5 0.5) reflection. These observations, aided by modeling, were cited as evidence for a separate chiral transition. In this Comment, we show that the prior conclusions based on x-ray diffraction are erroneous. There is just one transition, and it is achiral.
@article{arxiv.1903.11120,
title = {Comment on "Chiral Phase Transition in Charge Ordered 1T-TiSe2" and Supplementary Material on "First-order Forbidden X-ray Diffraction"},
author = {Meng-Kai Lin and Joseph A. Hlevyack and Peng Chen and Ro-Ya Liu and T. -C. Chiang},
journal= {arXiv preprint arXiv:1903.11120},
year = {2019}
}
Comments
Reference [1]: J. P. Castellan, et al., Phys. Rev. Lett. 110, 196404 (2013)