Perfect separation of intraband and interband excitations in PdCoO${}_2$

Abstract

The temperature dependence of the optical properties of the delafossite PdCoO${}_2$ has been measured in the a-b planes over a wide frequency range. The optical conductivity due to the free-carrier (intraband) response falls well below the interband transitions, allowing the plasma frequency to be determined from the $f$-sum rule. Drude-Lorentz fits to the complex optical conductivity yield estimates for the free-carrier plasma frequency and scattering rate. The in-plane plasma frequency has also been calculated using density functional theory. The experimentally-determined and calculated values for the plasma frequencies are all in good agreement; however, at low temperature the optically-determined scattering rate is much larger than the estimate for the transport scattering rate, indicating a strong frequency-dependent renormalization of the optical scattering rate. In addition to the expected in-plane infrared-active modes, two very strong features are observed that are attributed to the coupling of the in-plane carriers to the out-of-plane longitudinal optic modes.

arXiv comment7 pages with five figures and three tables; 4 pages of supplementary material

References in corpus (8)

• Evidence for hydrodynamic electron flow in PdCoO${}_2$
• Universality of the Mott-Ioffe-Regel limit in metals
• The properties of ultrapure delafossite metals
• Quantum oscillations and high carrier mobility in the delafossite PdCoO${}_2$
• Unconventional Anomalous Hall Effect in the Metallic Triangular-Lattice Magnet PdCrO2
• On the metallic conductivity of the delafossites PdCoO2 and PtCoO2
• Electrodynamics of correlated electron matter
• FeTe${}_{0.55}$Se${}_{0.45}$: a multiband superconductor in the clean and dirty limit

Cited by in corpus (6)

• Anisotropic Scattering in Goniopolar Metal NaSn${}_2$As${}_2$
• Finite-size effects of electron transport in PdCoO${}_2$
• Unraveling the unusually high electrical conductivity of the delafossite metal PdCoO${}_2$
• Fully two-dimensional incommensurate charge modulation on the Pd-terminated polar surface of PdCoO2
• Dichotomy of electron-phonon interactions in the delafossite PdCoO${}_2$: From weak bulk to polaronic surface coupling
• Disorder-enhanced effective masses and deviations from Matthiessen's rule in PdCoO${}_2$ thin films