Theory of phonon-assisted forbidden optical transitions in spin-gap systems

2004/01/14 by O. Cépas, Olivier Cepas, Timothy Ziman · 1 citation
Chemistry · Engineering · Mathematics · Physics and Astronomy · #Chemistry #Condensed matter physics #Dipole #Electric dipole transition #Excitation #Magnetic dipole #Magnetic properties of thin films #Magneto-Optical Properties and Applications #Mathematics #Operator (biology) #Phonon #Physics #Physics of Superconductivity and Magnetism #Point reflection #Polarization (electrochemistry) #Quantum mechanics #Spin (aerodynamics) #Symmetry (geometry) #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.70.024404

published as Phys. Rev. B 70, 024404 (2004) · 9 pages, 4 figures

arxiv created 2004/01/14 · openalex publication_date 2004/07/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We consider the absorption of light with emission of one S_tot=1 magnetic excitation in systems with a spin gap induced by quantum fluctuations. We argue that an electric-dipole transition is allowed on the condition that a virtual phonon instantaneously breaks the inversion symmetry. We derive an effective operator for the transition and argue that the proposed theory explains the polarized experiments in CuGeO₃ and SrCu₂(BO₃)₂.

Citations

• Dynamics in the dimerized and the high-field incommensurate phase of CuGeO3
• A thermodynamic theory of “weak” ferromagnetism of antiferromagnetics
• Dzyaloshinski-Moriya Interaction in the 2D Spin Gap SystemSrCu2(BO3)2
• Anisotropic Superexchange Interaction and Weak Ferromagnetism

Cited by

• Electrodynamics of correlated electron materials