2010/02/10 by N. Hlubek, M. Sing, S. Glawion +7
Physics and Astronomy · #Anisotropy #Condensed matter physics #Conductivity #Coupling (piping) #Cuprate #Lattice (music) #Magnetic field #Materials science #Phase (matter) #Phase transition #Phonon #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Spin (aerodynamics) #Superconductivity #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.81.144428
published as Phys. Rev. B 81, 144428 (2010) · 6 pages, 3 figures
arxiv created 2010/02/10 · openalex publication_date 2010/04/28 · arxiv updated 2010/04/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report experimental results on the heat conductivity \ensuremathκ of the S=1/2 spin chain compounds TiOBr and TiOCl for temperatures 5 K<T<300 K and magnetic fields up to 14 T. Surprisingly, we find no evidence of a significant magnetic contribution to \ensuremathκ, which is in stark contrast to recent results on S=1/2 spin chain cuprates. Despite this unexpected result, the thus predominantly phononic heat conductivity of these spin-Peierls compounds exhibits a very unusual behavior. In particular, we observe strong anomalies at the phase transitions Tc1 and Tc2. Moreover, we find an overall but anisotropic suppression of \ensuremathκ in the intermediate phase which extends even to temperatures higher than Tc2. An external magnetic field causes a slight downshift of the transition at Tc1 and enhances the suppression of \ensuremathκ up to Tc2. We interpret our findings in terms of strong spin-phonon coupling and phonon scattering arising from spin-driven lattice distortions.