标题： 无限层镍氧化物化合物的相图来自第一性原理和第二性原理计算 显示英文标题

标题： Phase Diagram of Infinite-layer Nickelate Compounds from First- and Second-principles Calculations

摘要： 无限层稀土镍氧化物（RNiO2）的基本性质被仔细回顾并与CaCuO2和RNiO3钙钛矿进行比较。 结合第一性原理和有限温度第二性原理计算，我们强调体相NdNiO2化合物与CaCuO2并不等价，从结构、电子和磁性层面来看均如此。 在结构上，它表现出容易发生自旋-声子耦合引起的氧方形旋转运动，这可能负责电阻率的显著上升。 在电子和磁性层面，我们指出具有强垂直带宽分散的轨道选择性莫特局域化，这应该导致各向同性的上临界磁场以及弱三维磁相互作用，包括平面内局域磁矩和垂直方向巡游磁矩。 我们进一步证明，正如在RNiO3钙钛矿中一样，氧旋转运动和稀土离子控制的电子和磁性特性可以在RNiO2化合物中产生丰富的相图和各种吸引人的特性的高可调性。 与此一致，我们揭示了高温超导体的关键成分，如轨道极化、费米面和反铁磁相互作用，可以通过外延应变在NdNiO2中被刻意控制。 利用应变-轨道工程，可以建立从三维到二维磁性转变的交叉，使NdNiO2薄膜成为高温铜氧化物超导体的真实类比。 显示英文摘要

摘要： The fundamental properties of infinite-layer rare-earth nickelates (RNiO2) are carefully revisited and compared with those of CaCuO2 and RNiO3 perovskites. Combining first-principles and finite-temperature second-principles calculations, we highlight that bulk NdNiO2 compound are far from equivalent to CaCuO2, together at the structural, electronic, and magnetic levels. Structurally, it is shown to be prone to spin-phonon coupling induced oxygen square rotation motion, which might be responsible for the intriguing upturn of the resistivity. At the electronic and magnetic levels, we point out orbital-selective Mott localization with strong out-of-plane band dispersion, which should result in the isotropic upper critical fields and weakly three-dimensional magnetic interactions with in-plane local moment and out-of-plane itinerant moment. We further demonstrate that as in RNiO3 perovskites, oxygen rotation motion and rare-earth ion controlled electronic and magnetic properties can give rise in RNiO2 compounds to a rich phase diagram and high tunability of various appealing properties. In line with that, we reveal that key ingredients of high-Tc superconductor such as orbital polarization, Fermi surface, and antiferromagnetic interactions can be deliberately controlled in NdNiO2 through epitaxial strain. Exploiting strain-orbital engineering, a crossover from three- to two-dimensional magnetic transition can be established, making then NdNiO2 thin film a true analog of high-Tc cuprates.