论文标题
通过多模耦合在氧化物界面的工程多功能
Engineering multifunctionality at oxide interfaces by multimode coupling
论文作者
论文摘要
我们采用了通过小组理论分析引导的第一原理密度功能理论计算，并证明了绝缘子 - 金属绝缘体的过渡，极化和两个Sublattice磁化（Lafeo $ _3 $）$ _ 1 $/（Cafeo $ _3 $ _3 $）$ _ 1 1 $ _ 1 $ superlattice。多结构模式耦合，即“多模耦合”。 We have discovered a polar A-type charge disproportionation mode, Q$_{ACD}$ (analogous to the A-type antiferromagnetic ordering), and found that it couples with the trilinear coupling, $Q_{Tri}$ mode (common in $Pnma$ perovskite oxides and involves three structural modes), and lowers the symmetry further.通过调整参与模式之间的耦合强度，可以获得极性金属相，极性零带隙半导体和极性绝缘阶段。在这里，$ q_ {tri} $切换了极化方向，而q $ _ {acd} $可以触发绝缘子 - 金属构造器的过渡以及偏振切换。对于由$ pnma $构建块组成的任何过渡金属超级晶格，并部分填充$ e_g $或$ t_ {2g} $ electeron在过渡金属站点上。
We employed first-principles density functional theory calculations guided by group-theoretical analysis and demonstrated the control of insulator-metal-insulator transition, polarization and two sublattice magnetization in (LaFeO$_3$)$_1$/(CaFeO$_3$)$_1$ superlattice via. multi structural mode coupling i.e., 'multimode coupling'. We have discovered a polar A-type charge disproportionation mode, Q$_{ACD}$ (analogous to the A-type antiferromagnetic ordering), and found that it couples with the trilinear coupling, $Q_{Tri}$ mode (common in $Pnma$ perovskite oxides and involves three structural modes), and lowers the symmetry further. By tuning the strength of the coupling between the participating modes, the polar metallic phase, polar zero bandgap semiconducting, and polar insulating phases can be obtained. Here, $Q_{Tri}$ switches the polarization direction, whereas, Q$_{ACD}$ can trigger insulator-metal-insulator transition along with the polarization switching. The mechanism is true for any transition metal superlattices constituted with $Pnma$ building blocks and with partially filled $e_g$ or $t_{2g}$ electron(s) at the transition metal sites.
