Longitudinal magnon in the tetrahedral spin systemCu2Te2O5Br2near quantum criticality

2003/01/28 by C. Gros, P. Lemmens, Matthias Vojta +15 · 1 citation
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Chemistry #Condensed matter physics #Crystallography #Energy (signal processing) #Excited state #Ferromagnetism #Geometry #Inverse #Magnetic and transport properties of perovskites and related materials #Magnon #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Singlet state #Spin (aerodynamics) #Tetrahedron #Thermodynamics #cond-mat.mtrl-sci #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.67.174405

published as PRB, Vol. 67, 174405 (2003).

arxiv created 2003/01/28 · openalex publication_date 2003/05/08 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We present a comprehensive study of the coupled tetrahedra compound Cu₂Te₂O₅Br₂ by theory and experiments in external magnetic fields. We report the observation of a longitudinal magnon in Raman scattering in the ordered state close to quantum criticality. We show that the excited tetrahedral-singlet sets the energy scale for the magnetic ordering temperature T_N. This energy is determined experimentally. The ordering temperature T_N has an inverse-log dependence on the coupling parameters near quantum criticality.

Citations

• Magnetic properties and spin waves of bilayer magnets in a uniform field
• Evidence for an Unconventional Magnetic Instability in the Spin-Tetrahedra SystemCu2Te2O5Br2
• A thermodynamic theory of “weak” ferromagnetism of antiferromagnetics
• Low energy singlets in the excitation spectrum of the spin tetrahedra system Cu2Te2O5Br2
• Anisotropic Superexchange Interaction and Weak Ferromagnetism

Cited by

• Anomalous frequency and intensity scaling of collective and local modes in a coupled-spin tetrahedral systemCu2Te2O5Cl2