Optical study of MgTi${}_2$O${}_4$: Evidence for an orbital-Peierls state

Abstract

Dimension reduction due to the orbital ordering has recently been proposed to explain the exotic charge, magnetic and structural transitions in some three-dimensional (3D) transitional metal oxides. We present optical measurement on a spinel compound MgTi${}_2$O${}_4$ which undergoes a sharp metal-insulator transition at 240 K, and show that the spectral change across the transition can be well understood from the proposed picture of 1D Peierls transition driven by the ordering of $d_{yz}$ and $d_{zx}$ orbitals. We further elaborate that the orbital-driven instability picture applies also very well to the optical data of another spinel CuIr${}_2$S${}_4$ reported earlier.

arXiv comment5 pages, 6 figures, to be published in Phys. Rev. B

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Cited by in corpus (10)

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• Emergent superconductivity in single crystalline ${\mathrm{MgTi}}_2{\mathrm{O}}_4$ films via structural engineering
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• Ionic liquid gating induced two superconductor-insulator phase transitions in spinel oxide Li${}_{1\pm x}$Ti${}_2$O${}_{4-\delta }$
• Prediction for the singlet-triplet excitation energy for the spinel MgTi${}_2$O${}_4$ using first-principles diffusion Monte Carlo
• Magnetic, Thermal, and Transport Properties of the Mixed Valent Vanadium Oxides LuV4O8 and YV4O8
• On the complexity of spinels: Magnetic, electronic, and polar ground states
• Frustrated Kondo chains and glassy magnetic phases on the pyrochlore lattice
• Evolution of orbital excitations from insulating to superconducting MgTi${}_2$O${}_4$ films
• Exploring the Electronic Nature of Spinel Oxides: A Review of Their Electron Interactions and Prospects