Spin-dependent charge dynamics of an orbital-spin-coupled system: Yb2 V2 O7

Optical conductivity spectra of ferromagnetic pyrochlore vanadate Yb2 V2 O7 were investigated under a variation of both temperature and magnetic field. It was found that the spectrum of a Mott-gap excitation, a d - d transition between neighboring V sites, exhibits spectral weight transfer to lower energies with ferromagnetic ordering as well as an applied magnetic field. This result indicates that charge dynamics is influenced by the spin state in this prototypical orbital-spin-coupled system.