Electrons in conventional metals become less mobile under the influence of electron correlation. Contrary to this empirical knowledge, we report here that electrons with the highest mobility ever found in known bulk oxide semiconductors emerge in the strong-correlation regime of the Dirac semimetal of perovskite CaIrO3. The transport measurements reveal that the high mobility exceeding 60,000 cm2V−1s−1 originates from the proximity of the Fermi energy to the Dirac node (ΔE < 10 meV). The calculation based on the density functional theory and the dynamical mean field theory reveals that the energy difference becomes smaller as the system approaches the Mott transition, highlighting a crucial role of correlation effects cooperating with the spin-orbit coupling. The correlation-induced self-tuning of Dirac node enables the quantum limit at a modest magnetic field with a giant magnetoresistance, thus providing an ideal platform to study the novel phenomena of correlated Dirac electron.
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机译：常规金属中的电子在电子相关性的影响下流动性降低。与这种经验知识相反，我们在此报告，在钙钛矿CaIrO3的狄拉克半金属的强相关体系中出现了在已知的体氧化物半导体中发现的具有最高迁移率的电子。输运测量表明，超过60,000 cm 2 V -1 s -1 的高迁移率源于费米能量与狄拉克的接近节点（ΔE<10 meV）。基于密度泛函理论和动力学平均场理论的计算表明，当系统接近莫特跃迁时，能量差变小，突出了相关效应与自旋轨道耦合协同作用的关键作用。相关诱导的狄拉克节点自整定使适度磁场下的量子极限具有巨大的磁阻，从而为研究相关狄拉克电子的新颖现象提供了理想的平台。
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