Probing orbital fluctuations in RVO3 (R = Y, Gd, or Ce) by ellipsometry

Abstract

We study optical excitations across the Mott gap in the multi-orbital Mott-Hubbard insulators RVO3. The multi-peak structure observed in the optical conductivity can be described consistently in terms of the different 3d^3 multiplets or upper Hubbard bands. The spectral weight is very sensitive to nearest-neighbor spin-spin and orbital-orbital correlations and thus shows a pronounced dependence on both temperature and polarization. Comparison with theoretical predictions based on either rigid orbital order or strong orbital fluctuations clearly rules out the latter. Both, the line shape and the temperature dependence give clear evidence for the importance of excitonic effects.

6 pages, 3 figures; extended discussion of Hubbard exciton

References in corpus (11)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Orbital fluctuations in the different phases of LaVO3 and YVO3
• Combining DFT and Many-Body Methods to Understand Correlated Materials
• Neutron diffraction study of YVO3, NdVO3, and TbVO3
• Theory of optical spectral weights in Mott insulators with orbital degrees of freedom
• Structural, electronic, and magneto-optical properties of YVO${}_3$
• One-dimensional orbital fluctuations and the exotic magnetic properties of YVO${}_3$
• Doping variation of anisotropic charge and orbital dynamics in Y1-xCaxVO3 : Comparison with La1-xSrxVO3
• Mott-Hubbard versus charge-transfer behavior in LaSrMnO4 studied via optical conductivity
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• Dispersion of the dielectric function of a charge-transfer insulator

Cited by in corpus (20)

• Hubbard exciton revealed by time-domain optical spectroscopy
• Emergent ultrafast phenomena in correlated oxides and heterostructures
• Orbital superexchange and crystal field simultaneously at play in YVO3: resonant inelastic x-ray scattering at the V L edge and the O K edge
• Influence of spin and orbital fluctuations on Mott-Hubbard exciton dynamics in LaVO${}_3$ Thin Films
• Phase separation in the non-equilibrium Verwey transition in magnetite
• Defect-induced orbital polarization and collapse of orbital order in doped vanadium perovskites
• Temperature-dependent optical conductivity of layered LaSrFeO_4
• Low temperature enhancement of ferromagnetic Kitaev correlations in α-RuCl3
• Signatures of spin-orbital states of ${t_{2g}}^2$ system in the optical conductivity : The case of $R$VO${}_3$ ($R$=Y and La)
• Lattice distortion in the spin-orbital entangled state in RVO3 perovskites
• Electronic excitations in $5d^4$ J=0 Os${}^{4+}$ halides studied by RIXS and optical spectroscopy
• Spin-orbit coupling and crystal-field splitting in Ti-doped Ca2RuO4 studied by ellipsometry
• Resonant inelastic x-ray scattering study of doping and temperature dependence of low-energy excitations in La${}_{1-x}$Sr${}_x$VO${}_3$
• Spin-orbit coupling in a half-filled $t_{2g}$ shell: the case of $5d^3$ K${}_2$ReCl${}_6$
• Spin-orbital-lattice entanglement in the ideal j=1/2 compound K${}_2$IrCl${}_6$
• Imprinted atomic displacements drive spin-orbital order in a vanadate perovskite
• Coupling of electronic and structural degrees of freedom in vanadate superlattices
• Low-energy V t2g orbital excitations in NdVO3
• $d-p$ model and spin-orbital order in the vanadium perovskites
• Tracking the local order parameter through the Hubbard exciton decoherence time in the Mott-Hubbard insulator LaVO3