论文类型：期刊论文
第一作者：Ching Hua Lee
通讯作者：Jiangbin Gong,Xiao Zhang
合写作者：Gang Xu,Tommy Tai,Han Hoe Yap
发表刊物：Physical Review B
收录刊物：SCI
学科门类：理学
一级学科：物理学
文献类型：J
卷号：102
期号：3
页面范围：35138
ISSN号：2469-9950
发表时间：2020-07-21
影响因子：4.036
摘要：Among topological materials, nodal loop semimetals are arguably the most topologically sophisticated, with their valence and conduction bands intersecting along arbitrarily intertwined nodes. But unlike the well-known topological band insulators with quantized edge conductivities, nodal loop materials possess topologically nontrivial Fermi surfaces, not bands. Hence an important question arises: Are there also directly measurable or even technologically useful physical properties characterizing nontrivial nodal loop topology? In this paper, we provide an affirmative answer by showing that nodal linkages protect the higher harmonic generation (HHG) of electromagnetic signals. Specifically, nodal linkages enforce nonmonotonicity in the intraband semiclassical response of nodal materials, which will be robust against perturbations preserving the nodal topology. These nonlinearities distort incident radiation and produce higher frequency peaks in the teraHertz (THz) regime, as we quantitatively demonstrate for a few known nodal materials. Since THz sources are not yet ubiquitous, our new mechanism for HHG will greatly aid applications like material characterization and nonionizing imaging of object interiors.
发布期刊链接：https://journals.aps.org/prb/abstract/10.1103/PhysRevB.102.035138