Relativistic aspects of orbital and magnetic anisotropies in the chemical bonding and structure of lanthanide molecules
Relativistic aspects of orbital and magnetic anisotropies in the chemical bonding and structure of lanthanide molecules
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DOI：
10.1088/1367-2630/ac1a9a
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发表时间：
2021-07
影响因子：
3.3
通讯作者：
E. Tiesinga;J. Kłos;Ming Li;A. Petrov;S. Kotochigova
中科院分区：
文献类型：
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作者：
E. Tiesinga;J. Kłos;Ming Li;A. Petrov;S. Kotochigova
磁性镧系元素原子的电子结构从基本的角度来看是迷人的。它们的电子在一个淹没的开放的4f壳层中，位于一个充满的6s壳层下面，具有强的相对论相关性，导致大的磁矩和大的电子轨道角动量。这种大的角动量导致强的各向异性，即。e.方向依赖性，在它们的相互作用。长程分子各向异性对于在基于自旋的量子计算机中使用超冷镧系元素原子、在相关物质中实现奇异态以及在磁性技术中发现的轨道电子学模拟的提议至关重要。这些原子物种之间的短程相互作用和键形成迄今尚未得到很好的表征。需要有效的相对论计算。在这里，我们第一次从理论上确定的电子和振转态的重homopolytic镧系元素Er 2和Tm 2分子应用国家的最先进的相对论方法。尽管它们的内部结构的复杂性，我们能够获得可靠的自旋轨道和相关诱导分裂之间的91 Er 2和36 Tm 2电子势解离为两个基态原子。张量分析使我们能够扩展原子之间的潜在的7个自旋-自旋张量运营商简化未来的研究。张量算符的强度作为原子分离的函数，并解释了来自色散长程相互作用的强度之间的关系。最后用耦合通道法计算并分析了低能级的光谱相关振转能级。
The electronic structure of magnetic lanthanide atoms is fascinating from a fundamental perspective. They have electrons in a submerged open 4f shell lying beneath a filled 6s shell with strong relativistic correlations leading to a large magnetic moment and large electronic orbital angular momentum. This large angular momentum leads to strong anisotropies, i. e. orientation dependencies, in their mutual interactions. The long-ranged molecular anisotropies are crucial for proposals to use ultracold lanthanide atoms in spin-based quantum computers, the realization of exotic states in correlated matter, and the simulation of orbitronics found in magnetic technologies. Short-ranged interactions and bond formation among these atomic species have thus far not been well characterized. Efficient relativistic computations are required. Here, for the first time we theoretically determine the electronic and ro-vibrational states of heavy homonuclear lanthanide Er2 and Tm2 molecules by applying state-of-the-art relativistic methods. In spite of the complexity of their internal structure, we were able to obtain reliable spin–orbit and correlation-induced splittings between the 91 Er2 and 36 Tm2 electronic potentials dissociating to two ground-state atoms. A tensor analysis allows us to expand the potentials between the atoms in terms of a sum of seven spin–spin tensor operators simplifying future research. The strengths of the tensor operators as functions of atom separation are presented and relationships among the strengths, derived from the dispersive long-range interactions, are explained. Finally, low-lying spectroscopically relevant ro-vibrational energy levels are computed with coupled-channels calculations and analyzed.