Photoemission and dynamical mean field theory study of electronic correlations in a t2g5 metal SrRhO3 thin film
Photoemission and dynamical mean field theory study of electronic correlations in a t2g5 metal SrRhO3 thin film
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DOI：
10.1103/physrevb.101.085134
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发表时间：
2019-07
影响因子：
3.7
通讯作者：
Yujun Zhang;Minjae Kim;J. Mravlje;C. Sohn;Yongseong Choi;J. Strempfer;Y. Hotta;A. Yasui;J. Nichols;Ho Nyung Lee;H. Wadati
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文献类型：
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作者：
Yujun Zhang;Minjae Kim;J. Mravlje;C. Sohn;Yongseong Choi;J. Strempfer;Y. Hotta;A. Yasui;J. Nichols;Ho Nyung Lee;H. Wadati
钙钛矿菱铁矿具有中等强度的电子关联和自旋轨道耦合(SOC)，通常表现为中等关联的金属。最近的一份出版物(Phys.Rev.B 95,245121(2017年))在外延的SrRhO$3$薄膜上意外地报告了不良的金属行为，并暗示在100K以下发生了反铁磁性。我们用硬X射线光电子能谱研究了这种薄膜，发现在费米能级上有很小的态密度，这与已报道的不良金属行为是一致的。然而，这种可以忽略的DOS可以持续到室温，这与100K左右的反铁磁相变的解释相矛盾。我们还在密度泛函理论和动力学平均场理论的框架下对电子结构进行了计算。与实验结果相比，我们的计算结果显示了体相和薄膜的金属行为。薄膜表现出比块体更强的关联效应，但关联效应不足以驱动向绝缘态的转变。计算得到的薄膜中的均匀磁化率比块体中的大得多。还研究了SOC的作用，只观察到电子结构的适度调制。因此，预计SOC不会在SrRhO$3$中的电子关联中发挥重要作用。
Perovskite rhodates are characterized by intermediate strengths of both electronic correlation as well as spin-orbit coupling (SOC) and usually behave as moderately correlated metals. A recent publication (Phys. Rev. B 95, 245121(2017)) on epitaxial SrRhO$_3$ thin films unexpectedly reported a bad-metallic behavior and suggested the occurrence of antiferromagnetism below 100 K. We studied this SrRhO$_3$ thin film by hard x-ray photoemission spectroscopy and found a very small density of states (DOS) at Fermi level, which is consistent with the reported bad-metallic behavior. However, this negligible DOS persists up to room temperature, which contradicts with the explanation of antiferromagnetic transition at around 100 K. We also employed electronic structure calculations within the framework of density functional theory and dynamical mean-field theory. In contrast to the experimental results, our calculations indicate metallic behavior of both bulk SrRhO$_3$ and the SrRhO$_3$ thin film. The thin film exhibits stronger correlation effects than the bulk, but the correlation effects are not sufficient to drive a transition to an insulating state. The calculated uniform magnetic susceptibility is substantially larger in the thin film than that in the bulk. The role of SOC was also investigated and only a moderate modulation of the electronic structure was observed. Hence SOC is not expected to play an important role for electronic correlation in SrRhO$_3$.