发表机构
University of Maryland（马里兰大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过理论分析，关联Haldane模型与手征超导体中环电流和交流霍尔电导率的光学特性，为实验测量环电流提供了方法，明确了光吸收峰的起源及与环电流的关系。
AI 中文摘要
我们对Haldane模型与时间反演对称性破缺超导体中环电流的光学表现开展理论研究。针对Haldane模型，我们依据模型参数计算环电流的期望值，并将其与频率相关的交流霍尔电导率的积分光学权重关联，因此对后者的实验测量可获取系统中稳态环电流的存在性与大小信息。随后，我们详细阐述Brydon等人（2019）此前研究的蜂窝晶格手征超导体中的环电流，证明交流霍尔电导率中的尖锐光吸收峰源于时间反演对称性破缺超导性激活的下、上狄拉克带间的激发，该峰的频率为费米能级与狄拉克点间能量差的2倍；该峰的光学权重与手征超导配对在原胞中诱导的环电流大小直接相关，与Haldane模型的情况类似。
英文摘要
We present a theoretical study of optical manifestations of loop currents in Haldane's model and in time-reversal-breaking superconductors. For Haldane's model, we calculate the expectation value of loop currents in terms of model parameters and relate it with the integrated optical spectral weight for the frequency-dependent ac Hall conductivity. Thus, experimental measurements of the latter can provide information about the presence and magnitude of steady loop currents in the system. Then we elaborate on loop currents in a chiral superconductor on the honeycomb lattice, studied earlier by Brydon et al. (2019). We demonstrate that a sharp optical absorption peak in the ac Hall conductivity originates from excitations between the lower and upper Dirac bands, activated by the time-reversal-breaking superconductivity. The frequency of the peak is twice the energy difference between the Fermi level and the Dirac point. The optical spectral weight of the peak is directly related to the magnitude of loop currents induced in the unit cells by the chiral superconducting pairing, in similarity to Haldane's model.
CommentsV.1: 24 pages, 9 figures. An invited paper submitted to a special issue on Loop Currents to be published by World Scientific. V.2: 28 pages, 9 figures. Appendix C and many references added. A popular summary is available at https://gist.science/paper/2608.22083. V.3: 29 pages, 9 figures. Some equations are corrected, and titles of papers are now shown in references
