论文标题
掺杂的旋转轨道耦合莫特绝缘子SR $ _2 $ iro $ _4 $中的非型狄拉克半米和载体动力学
Nonsymmorphic Dirac semimetal and carrier dynamics in doped spin-orbit-coupled Mott insulator Sr$_2$IrO$_4$
论文作者
论文摘要
凝结物质中对称性与拓扑之间的相互作用，出现了狄拉克·费米昂（Dirac Fermion）。当前的研究朝着在相关系统中存在许多身体效应的情况下调查狄拉克费物的发展。在这里，我们证明了相关诱导的对称性保护的狄拉克半学状态的出现，该状态在轻度的旋转摩托耦合莫特绝缘子SR $ _2 $ IRO $ _4 $中的出现。我们发现，非词形结晶对称性稳定了狄拉克线节点的半学，并且相关诱导的对称性破坏的电子序列进一步导致从狄拉克线节点到狄拉克点节点半段的相变。后一种状态通过角度分辨的光发射光谱和SR $ _2 $（IR，TB）O $ _4 $和（SR，LA）$ _ 2 $ IRO $ _4 $在实验上证实。值得注意的是，即使在室温下，相对论的准粒子的标志性行为，无数dirac载体的电动力学受到约6 cm $^{ - 1} $的极小散射率的控制。电动动力参数的温度依赖性变化也始终基于狄拉克点节点的半学状态来解释。
A Dirac fermion emerges as a result of interplay between symmetry and topology in condensed matter. Current research moves towards investigating the Dirac fermions in the presence of manybody effects in correlated system. Here, we demonstrate the emergence of correlation-induced symmetry-protected Dirac semimetal state in the lightly-doped spin-orbit-coupled Mott insulator Sr$_2$IrO$_4$. We find that the nonsymmorphic crystalline symmetry stabilizes a Dirac line-node semimetal and that the correlation-induced symmetry-breaking electronic order further leads to a phase transition from the Dirac line-node to a Dirac point-node semimetal. The latter state is experimentally confirmed by angle-resolved photoemission spectroscopy and terahertz spectroscopy on Sr$_2$(Ir,Tb)O$_4$ and (Sr,La)$_2$IrO$_4$. Remarkably, the electrodynamics of the massless Dirac carriers is governed by the extremely small scattering rate of about 6 cm$^{-1}$ even at room temperature, which is iconic behavior of relativistic quasiparticles. Temperature-dependent changes in electrodynamic parameters are also consistently explained based on the Dirac point-node semimetal state.
