Optical conductivity of the metallic pyrochlore iridate Pr${}_2$Ir${}_2$O${}_7$: Influence of spin-orbit coupling and electronic correlations on the electronic structure

Abstract

The synergy of strong spin-orbit coupling and electron-electron interactions gives rise to unconventional topological states, such as topological Mott insulator, Weyl semimetal, and quantum spin liquid. In this study, we have grown single crystals of the pyrochlore iridate Pr${}_2$Ir${}_2$O${}_7$ and explored its magnetic, lattice dynamical, and electronic properties. While Raman spectroscopy data reveal six phonon modes confirming the cubic \textit{Fd$\bar{3}$m} crystal symmetry, dc magnetic susceptibility data show no anomalies and hence indicate the absence of magnetic phase transitions down to 2~K. Both temperature-dependent electric transport and optical conductivity data reveal the metallic character of Pr${}_2$Ir${}_2$O${}_7$. The optical conductivity spectrum contains a mid-infrared absorption band, which becomes more pronounced with decreasing temperature due to spectral weight transfer from high to low energies. The presence of the mid-infrared band hints at the importance of correlation physics. The optical response furthermore suggests that Pr${}_2$Ir${}_2$O${}_7$ is close to the Weyl semimetal phase.

arXiv comment11 pages, 8 figures, accepted for publication in Phys. Rev. B

References in corpus (37)

• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Correlated quantum phenomena in the strong spin-orbit regime
• Mott physics and band topology in materials with strong spin-orbit interaction
• Kramers-Kronig constrained variational analysis of optical spectra
• Electrodynamics of Correlated Electron Materials
• Bandwidth-Controlled Insulator-Metal Transition and Correlated Metallic State in 5$d$ Transition Metal Oxides Sr${}_{n+1}$Ir${}_n$O${}_{3n+1}$ ($n$=1, 2, and $\infty$)
• Charge Transport in Weyl Semimetals
• Non-Fermi liquid and topological states with strong spin-orbit coupling
• Transport properties of strongly correlated metals:a dynamical mean-field approach
• Quadratic Fermi Node in a 3D Strongly Correlated Semimetal
• Optical evidence for a Weyl semimetal state in pyrochlore Eu2Ir2O7
• Use of X-ray scattering functions in Kramers-Kronig analysis of reflectance
• Quantum criticality in a metallic spin liquid
• A New Type of Quantum Criticality in the Pyrochlore Iridates
• Many-body large polaron optical conductivity in SrTi${}_{1-x}$Nb${}_x$O${}_3$
• Optical investigation on the electronic structures of Y_{2}Ru_{2}O_{7}, CaRuO_{3}, SrRuO_{3}, and Bi_{2}Ru_{2}O_{7}
• Evolution of a polaron band through the phase diagram of Nd[2-x]Ce[x]CuO[4-y]
• Low frequency optical conductivity in graphene and in other scale-invariant two-band systems
• Competing orders and topology in the global phase diagram of pyrochlore iridates
• Dielectric anomalies and interactions in the 3D quadratic band touching Luttinger semimetal Pr${}_2$Ir${}_2$O${}_7$
• Mechanism of enhanced optical second-harmonic generation in the conducting pyrochlore-type Pb${}_2$Ir${}_2$O${}_{7-x}$ oxide compound
• Comparative studies of low temperature X-ray diffraction experiments on R2Ir2O7 (R = Nd, Eu, and Pr)
• Electronic correlations in iron-pnictide superconductors and beyond; what can we learn from optics
• Evolution of structure, magnetism and electronic transport in doped pyrochlore iridate Y${}_2$Ir${}_{2-x}$Ru${}_x$O${}_7$
• Nonequilibrium low temperature phase in pyrochlore iridate Y${}_2$Ir${}_2$O${}_7$: Possibility of glass-like dynamics
• High-pressure versus isoelectronic doping effect on the honeycomb iridate Na${}_2$IrO${}_3$
• Signatures of polaronic excitations in quasi-one-dimensional LaTiO${}_{3.41}$
• Magnetic and transport properties in pyrochlore iridates (Y${}_{1-x}$Pr${}_x$)${}_2$Ir${}_2$O${}_7$: The role of $f$-$d$ exchange interaction and $d$-$p$ orbital hybridization
• Optical investigations on $Y_{2-x}B{i}_{x}R{u}_2{O}_7$: Electronic structure evolutions related to the metal-insulator transition
• Unconventional free charge in the correlated semimetal Nd2Ir2O7
• Optical signature of the pressure-induced dimerization in the honeycomb iridate $\alpha$-Li${}_2$IrO${}_3$
• Experimental signatures of versatile Weyl semimetal in pyrochlore iridate with spin-ice like magnetic orders
• Polaron physics and crossover transition in magnetite probed by pressure-dependent infrared spectroscopy
• Magnetic field tuning of the valley population in the Weyl phase of Nd${}_2$Ir${}_2$O${}_7$
• Infrared study of the layered, magnetic insulator Mn(Bi${}_{0.07}$Sb${}_{0.93}$)${}_2$Te${}_4$ at low temperatures
• Fluorite-related iridate Pr${}_3$IrO${}_7$: Crystal growth, structure, magnetism, thermodynamic, and optical properties

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