AI 中文总结
研究多种量子材料中回路电流相的检测问题，利用铜酸盐高温超导体和Sr₂RuO₄表面层模型，给出在光谱图中观察方形晶格中回路电流序的预测，发现自旋轨道耦合时的自旋极化特征可在自旋极化STM中检测。
AI 中文摘要
基于检测到的时间反演对称性破缺的微弱特征或小磁矩有序，有研究提出在多种量子材料中存在回路电流相，即轨道电流的自发回路产生微弱局部磁矩。其中最突出的例子是对高温铜酸盐超导体相图欠掺杂侧赝能隙相的解释。但目前实验结果尚无定论。低温扫描隧道显微镜和光谱学（STM/STS）应能检测回路电流序的局部特征，但缺乏如何检测的明确预测。本文利用铜酸盐高温超导体和Sr₂RuO₄表面层模型，给出了在光谱图中观察方形晶格中回路电流序的具体预测。发现除了在回路电流序的特定有序矢量处解除简并外，当存在自旋轨道耦合时会出现有限的自旋极化，其特征可在自旋极化STM中检测到。
英文摘要
The emergence of loop current phases, where spontaneous loops of orbital currents give rise to a weak local magnetic moments, has been proposed to exist in a number of quantum materials based on measurements that pick up weak signatures of time reversal symmetry breaking or small magnetic moment order. The most prominent example is as an explanation of the pseudogap phase on the underdoped side of the phase diagram of the high-temperature cuprate superconductors, but more recently, it has been proposed to occur in Kagome materials and at the surface layer of Sr$_2$RuO$_4$. Experimental results have, however, been inconclusive so far, some detecting signatures that can be understood as emerging due to loop current phases, whilst others have not detected any significant proof. One of the techniques that should be able to pick up local signatures of loop current orders is low temperature scanning tunneling microscopy and spectroscopy (STM/STS), however firm predictions of how to detect them are missing. Here, we provide specific predictions for how loop current orders in a square lattice can be seen in spectroscopic maps, using models of the cuprate high-temperature superconductors and of the surface layer of Sr$_2$RuO$_4$. We find that, besides lifting degeneracies at the specific ordering vector of the loop current order, a finite spin polarisation emerges when spin-orbit coupling is present, signatures of which can be detected in spin-polarised STM.
Comments8 pages, 4 figures, including Supplementary
