Abstract Submitted for the MAR07 Meeting of The American Physical Society Doping variation of orbitally-induced anisotropy in electronic structure of the perovskite-type vanadium oxides

Submitted for the MAR07 Meeting of The American Physical Society Doping variation of orbitally-induced anisotropy in electronic structure of the perovskite-type vanadium oxides JUN FUJIOKA, SHIGEKI MIYASAKA, Dept. of Appl. Phys., Univ. of Tokyo, YOSHINORI TOKURA, Dept. of Appl. Phys., Univ. of Tokyo, ERATO-SSS, AIST-CERC — Recently, the perovskite-type vanadium oxide LaVO3 has been attracting much attention. In this system, the anisotropic charge dynamics due to the one-dimensional orbital exchange interaction is observed. In addttion, the filling control insulator-metal transition (FC-IMT) concomitant with the orbital ordering-disordering transition can be achieved in the hole doped system La1−xSrxVO3[1]. In this study, the variation of anisotropic charge dynamics in the course of FC-IMT in the perovskite-type vanadium oxide has been investigated by measurements of optical conductivity spectra with focus on the role of t2g-orbital degree of freedom. The orbitally-induced anisotropic feature of the Mott-gap excitation as well as of the doping-induced midinfrared excitation is suppressed with increasing the hole concentration, and instead the isotropic and incoherent dynamics of the doped hole dominates over the lowenergy excitation near and above the IMT point. [1] S.Miyasaka et al., Phys.Rev.Lett. 85,5388(2000) Jun Fujioka Dept. of Appl. Phys., Univ. of Tokyo Date submitted: 13 Nov 2006 Electronic form version 1.4