Optical and photoelectrical studies on anisotropic metal-insulator transition of RuAs

Abstract

The anisotropic changes in the electronic structure of a metal-to-insulator transition (MIT) material, RuAs, with two-step phase transition are reported by using polarized optical conductivity [$\sigma (\omega )$] spectra, angle-integrated photoelectron (PE) spectra, and band calculations based on local density approximation (LDA). Both the PE and $\sigma (\omega )$ spectra not only in the high-temperature (HT) phase but also in the low-temperature (LT) phase as well as the energy gap formation owing to the MIT were almost consistent with those derived from the LDA band calculations, so the fundamental electronic structure in the HT and LT phases can be explained without electron correlations. However, the electronic structure in the middle phase between the HT and LT phases has not been clarified. The polarized $\sigma (\omega )$ spectra revealed not only the anisotropic energy gap formation but also the anisotropic gap-opening temperature, i.e., the energy gap along the $c$ axis in the HT phase starts to open near the higher transition temperature, but that along the $b$ axis opens below the lower transition temperature. The finding suggests that the two-step MIT originates from the anisotropic energy gap formation.

arXiv comment7 pages, 7 figures

References in corpus (8)

• Electronic-Structure-Driven Magnetic Ordering in a Kondo Semiconductor CeOs2Al10
• Properties of Binary Transition-Metal Arsenides (TAs)
• Optical signature of Weyl electronic structures in tantalum pnictides Ta$Pn$ ($Pn=$ P, As)
• Infrared and Terahertz Spectroscopy of Strongly Correlated Electron Systems under Extreme Conditions
• Metal-insulator transition and superconductivity induced by Rh doping in binary Ru Pnictides RuPn (Pn = P, As and Sb)
• Optical study of phase transitions in single-crystalline RuP
• Novel Electronic Structures of Ru-Pnictides Ru$Pn$ ($Pn$ = P, As, Sb)
• Superlattice formation lifting degeneracy protected by non-symmorphic symmetry through a metal-insulator transition in RuAs

Cited by in corpus (3)

• Linear Trimer Formation by Three-Center-Four-Electron Bonding in RuP
• Role of Local Ru Hexamers in Superconductivity of Ruthenium Phosphide
• First-order phase transition to a nonmagnetic ground state in nonsymmorphic NbCrP