@article{ade137cfb0ee4bfdbdb06d085e41bf68,
title = "Interaction of in-plane Drude carrier with c -axis phonon in PdCoO2",
abstract = "We performed polarized reflection and transmission measurements on the layered conducting oxide PdCoO2 thin films. For the ab-plane, an optical peak near Ω ≈ 750 cm−1 drives the scattering rate 1/τ(ω) and effective mass m*(ω) of the Drude carrier to increase and decrease respectively for ω ≧ Ω. For the c-axis, a longitudinal optical phonon (LO) is present at Ω as evidenced by a peak in the loss function Im[−1/εc(ω)]. Further polarized measurements in different light propagation (q) and electric field (E) configurations indicate that the Peak at Ω results from an electron-phonon coupling of the ab-plane carrier with the c-LO phonon, which leads to the frequency-dependent 1/τ(ω) and m*(ω). This unusual interaction was previously reported in high-temperature superconductors (HTSC) between a non-Drude, mid-infrared (IR) band and a c-LO. On the contrary, it is the Drude carrier that couples in PdCoO2. The coupling between the ab-plane Drude carrier and c-LO suggests that the c-LO phonon may play a significant role in the characteristic ab-plane electronic properties of PdCoO2, including the ultra-high dc-conductivity, phonon-drag, and hydrodynamic electron transport.",
author = "Dongmin Seo and Gihyeon Ahn and Gaurab Rimal and Seunghyun Khim and Chung, {Suk Bum} and Mackenzie, {A. P.} and Seongshik Oh and Moon, {S. J.} and Eunjip Choi",
note = "Funding: E.C. was supported by the NRF-2021R1A2C1009073 of Korea funded by the Ministry of Education. D.S. was partially supported by MOLIT as an Innovative Talent Education Program for Smart City. The work at Rutgers University is supported by the National Science Foundation{\textquoteright}s DMR2004125 and the Army Research Office{\textquoteright}s W911NF2010108. S.B.C. was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIT)(NRF-2023R1A2C1006144, NRF-2020R1A2C1007554, and NRF-2018R1A6A1A06024977). Research in Dresden benefits from the environment provided by the DFG Cluster of Excellence ct.qmat (EXC 2147, project ID 390858490). The work at HYU was supported by the NRF grant funded by the Korean government (MSIT) (2022R1F1A1072865), the BrainLink program funded by MSIT (2022H1D3A3A01077468), and the Quantum Simulator Development Project for Materials Innovation through the NRF funded by MSIT (2023M3K5A1094813).",
year = "2023",
month = dec,
day = "16",
doi = "10.1038/s41535-023-00607-1",
language = "English",
volume = "8",
journal = "npj Quantum Materials",
issn = "2397-4648",
publisher = "Nature publishing group",
}