Doublon-holon pairing mechanism via exchange interaction in two-dimensional cuprate Mott insulators.

ABSTRACT: Coupling of charge and spin degrees of freedom is a critical feature of correlated electron oxides, as represented by the spin-related mechanism of a Cooper pair under high-T _c superconductivity. A doublon-holon pair generated on an antiferromagnetic spin background is also predicted to attract each other via the spin-spin interaction J, similar to a Cooper pair, while its evidence is difficult to obtain experimentally. Here, we investigate such an excitonic effect by electroreflectance spectroscopy using terahertz electric field pulses in undoped cuprates: Nd₂CuO₄, Sr₂CuO₂Cl₂, and La₂CuO₄. Analyses of the spectral changes of reflectivity under electric fields reveal that the splitting of

SUBMITTER: Terashige T 

PROVIDER: S-EPMC6555625 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature