论文标题
Lamno中的铁磁绝缘状态的出现
Emergence of a ferromagnetic insulating state in LaMnO$_3$/SrTiO$_3$ heterostructures: The role of strong electronic correlations and strain
论文作者
论文摘要
受到lamno中异国情调的铁绝缘状态的实验发现的启发，我们计算了Lamno $ _3 $/srtio $ _3 $ _3 $超级层次的lamno $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ superlattices的电子和磁状态，其具有比较厚的厚度，该厚度使用AbiNitio dynamitio-Initiel dynamitiel dynamielieldield tirnieldield tirdield tirdield tirdield tirdield tirdield tirdield borytile。我们的方法预测了MN $ 3D $和TI $ 3D $州的低能子空间，并解决了多发性问题，我们的方法强调了MN和TI站点的本地相关性。我们发现，由于系统中强相关性的固有效应而与实验研究一致，因此出现铁磁绝缘状态。我们还预测，由于电子相关性，新出现的2D电子气体位于界面的LMO侧。这与将电子气体定位在Sto侧的DFT结果相反。我们估计顺磁性到铁磁相变的过渡温度，可以通过实验验证。重要的是，我们还澄清说，外延菌株是外来铁磁绝缘状态出现的关键要素。从对拉姆诺$ _3 $系统的计算中可以清楚地看出这一点，也显示了铁磁性，在未经培训的散装材料中看不到。
Inspired by the experimental findings of an exotic ferromagnetic insulating state in LaMnO$_3$/SrTiO$_3$ heterostructures, we calculate the electronic and magnetic state of LaMnO$_3$/SrTiO$_3$ superlattices with comparable thicknesses employing ab-initio dynamical mean-field theory. Projecting on the low-energy subspace of Mn $3d$ and Ti $3d$ states, and solving a multi-impurity problem, our approach emphasizes on local correlations at Mn and Ti sites. We find that a ferromagnetic insulating state emerges due to intrinsic effects of strong correlations in the system, in agreement with experimental studies. We also predict that, due to electronic correlations, the emerging 2D electron gas is located at the LMO side of the interface. This is in contrast to DFT results that locate the electron gas on the STO side. We estimate the transition temperature for the paramagnetic to ferromagnetic phase transition, which may be verified experimentally. Importantly, we also clarify that the epitaxial strain is a key ingredient for the emergence of the exotic ferromagnetic insulating state. This becomes clear from calculations on a strained LaMnO$_3$ system, also showing ferromagnetism which is not seen in the unstrained bulk material.
