Raman scattering and anomalous current algebra in Mott insulators

D. V. Khveshchenko, P. B. Wiegmann
1994 Physical Review Letters  
Recent experiments on inelastic light scattering in a number of insulating cuprates [1] revealed a new excitation appearing in the case of crossed polarizations just below the optical absorption threshold. This observation suggests that there exists a local exciton-like state with an odd parity with respect to a spatial reflection. We present the theory of high energy large shift Raman scattering in Mott insulators and interpret the experiment [1] as an evidence of a chiral bound state of a
more » ... and a doubly occupied site with a topological magnetic excitation. A formation of these composites is a crucial feature of various topological mechanisms of superconductivity. We show that inelastic light scattering provides an instrument for direct measurements of a local chirality and anomalous terms in the electronic current algebra.
doi:10.1103/physrevlett.73.500 pmid:10057462 fatcat:plcdxpknyvamncjoqyk2tboe7i