Doping variation of anisotropic charge and orbital dynamics in Y1-xCaxVO3 : Comparison with La1-xSrxVO3

Abstract

The doping variation of charge and orbital dynamics in perovskite-type Y1-xCaxVO3 (0<x<0.1) is investigated by measurements of the optical conductivity and Raman scattering spectra in comparison with the larger-bandwidth system La1-xSrxVO3. We also take into consideration the magnitude of the GdFeO3-type orthorhombic lattice distortion, which is large and small in Y1-xCaxVO3 and La1-xSrxVO3, respectively, and discuss its effect on the evolution of charge dynamics. The optical conductivity spectra show that the doped hole is well localized and forms the small polaron like state. The hole dynamics in Y1-xCaxVO3 is nearly isotropic up to the doping level of the orbital order-disorder transition, while that in La1-xSrxVO3 is anisotropic in the lightly doped region due to the one-dimensional orbital exchange interaction. The possible origin of the difference in the hole dynamics is discussed in terms of the local lattice distortion, which is induced by the formation of the small polaron like state and becomes more significant for the reduced one-electron bandwidth. In addition, the optical Mott-gap excitation in the nominally C-type spin and $G$-type orbital ordered phase is distinct from that for La1-xSrxVO3 in its intensity and spectral shape. This suggests that the orthorhombic lattice distortion enhances the modification of the spin and orbital ordering from the pure C-type and G-type, respectively. The systematic study of Raman scattering spectra has shown that the dynamic G-type spin and C-type orbital correlation subsists at low temperatures in the doping induced phase of the nominally C-type SO and G-type OO.

arXiv comment10 pages, 9 figures

References in corpus (16)

• Complexity in Strongly Correlated Electronic Systems
• On the Fermi Liquid to Polaron Crossover I: General Results
• ESR study in lightly doped La_(1-x)Sr_(x)MnO_(3)
• Spin Order due to Orbital Fluctuations: Cubic Vanadates
• Magnetic neutron scattering study of YVO3: Evidence for an orbital Peierls state
• Orbital fluctuations in the different phases of LaVO3 and YVO3
• Anisotropy of Mott-Hubbard gap transitions due to spin and orbital ordering in LaVO3 and YVO3
• Dimerization versus Orbital Moment Ordering in the Mott insulator YVO${}_3$
• Theory of optical spectral weights in Mott insulators with orbital degrees of freedom
• Structural, electronic, and magneto-optical properties of YVO${}_3$
• One-Dimensional Confinement and Enhanced Jahn-Teller Instability in LaVO${}_3$
• Evidence for electronic phase separation between orbital orderings in SmVO3
• Orbital Disordering and metal-insulator transition with hole-doping in perovskite-type vanadium oxides
• Anisotropic Optic Conductivities due to Spin and Orbital Orderings in LaVO3 and YVO3: First-Principles Studies
• Entropy Driven Dimerization in a One-Dimensional Spin-Orbital Model
• Hole dynamics in spin and orbital ordered vanadium perovskites

Cited by in corpus (23)

• Metal-Insulator phase diagram and orbital selectivity in 3-orbital models with rotationally invariant Hund coupling
• Spectral properties of orbital polarons in Mott insulators
• Magnetism and orbital-ordering in an interacting three band model: a dynamical mean field study
• Orbitally induced string formation in the spin-orbital polarons
• Spin-Orbital Order Modified by Orbital Dilution in Transition Metal Oxides: From Spin Defects to Frustrated Spins Polarizing Host Orbitals
• Probing orbital fluctuations in RVO3 (R = Y, Gd, or Ce) by ellipsometry
• Defect states and excitations in a Mott insulator with orbital degrees of freedom: Mott-Hubbard gap versus optical and transport gaps in doped systems
• Defect states and spin-orbital physics in doped vanadates Y1-xCaxVO3
• Novel Spin-Orbital Phases Induced by Orbital Dilution
• Defect-induced orbital polarization and collapse of orbital order in doped vanadium perovskites
• Spin-orbital order in LaMnO${}_3$: $d-p$ model study
• Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy
• Defects, disorder and strong electron correlations in orbital degenerate, doped Mott insulators
• Exotic Spin-Orbital Physics in Hybrid Oxides
• Effect of cation size variance on spin and orbital order in Eu${}_{1-x}$(La${}_{0.254}$Y${}_{0.746}$)${}_x$VO${}_3$
• Charge and orbital order in transition metal oxides
• Spin--orbital physics in transition metal oxides
• Resonant inelastic x-ray scattering study of doping and temperature dependence of low-energy excitations in La${}_{1-x}$Sr${}_x$VO${}_3$
• Exact spectral function for hole-magnon coupling in the ferromagnetic CuO${}_3$-like chain
• Orbital Rotations induced by Charges of Polarons and Defects in Doped Vanadates
• $d-p$ model and spin-orbital order in the vanadium perovskites
• Rare collapse of fermionic quasiparticles upon coupling to local bosons
• One-dimensional frustrated plaquette compass model: Nematic phase and spontaneous multimerization