Dirac polaron dynamics in the correlated semimetal of perovskite CaIrO3
Dirac polaron dynamics in the correlated semimetal of perovskite CaIrO3
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DOI：
10.1103/physrevb.103.l041109
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发表时间：
2021-01
影响因子：
3.7
通讯作者：
J. Fujioka;R. Yamada;T. Okawa;Y. Tokura
中科院分区：
文献类型：
--
作者：
J. Fujioka;R. Yamada;T. Okawa;Y. Tokura
用红外光谱研究了关联Dirac半金属钙钛矿${\mathrm{CaIrO}}_{3}$的电荷动力学。电导率谱显示了$\ensuremath{\omega}$-线性型带间跃迁和在低温下的微小Drude响应，这表明狄拉克节点被钉扎在费米能量附近，由于莫特临界。此外，一个大的极化子吸收出现在0.04 eV左右，当热激发载流子减少和等离子体频率降低到光学声子能量以下。电子关联和由此产生的降低的等离子体频率可能通过不充分的电子屏蔽增强电子-声子相互作用，实现狄拉克极化子。
We have investigated the charge dynamics of the correlated Dirac semimetallic perovskite ${\mathrm{CaIrO}}_{3}$ by infrared spectroscopy. The optical conductivity spectra show the $\ensuremath{\omega}$-linear-type interband transition and a tiny Drude response at low temperatures, suggesting that the Dirac node is pinned near the Fermi energy due to the Mott criticality. Moreover, a large polaron absorption appears at around 0.04 eV, when thermally excited carriers diminish and the plasma frequency decreases below the optical phonon energy. The electron correlation and resultant reduced plasma frequency are likely to enhance the electron-phonon interaction via the insufficient electronic screening, realizing the Dirac polaron.