Giant phonon softening in the pseudogap phase of the quantum spin system TiOCl
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
70
Journal Issue
13
Pages
134429-1-134429-5
Date Issued
2004
Author(s)
Abstract
Giant anomalies are found in the temperature dependence of Raman-active phonons in the quantum magnet TiOCl, suggesting the presence of an extended fluctuation regime. This regime coincides with a pseudogap phase identified in earlier NMR experiments. The observed large, local spin-gap is proposed to origin from coupled spin/lattice fluctuations. Below 100 K, in the long-range crystallographically distorted phase, a dimerized ground state with a smaller, global spin-gap of about 2Δspin ≈ 430 Êexists. This transition also marks a dimensionality cross-over of the system.
SDGs
Type
journal article