近日，南京大学陈延峰团队研究了二维反铁磁光子狄拉克半金属的单向体边界耦合。相关论文于2025年11月18日发表在《物理评论A》杂志上。

近期发现的反手性边缘态被束缚于一对具有不同简并能量的偏移狄拉克点，并沿平行边界呈现同向传播特性。然而，在无耗散系统的能量守恒框架下，针对其伴随的逆向体态传播行为的研究尚属罕见。

研究组通过制备二维蜂窝晶格反铁磁光子晶体，成功构建了光子狄拉克半金属体系。微波实验在狄拉克点频率附近同时观测到非互易体态与反手性边缘态。采用菱形样品结构，他们实现了体态-边界与边界-体态的单向耦合。进一步，他们还演示了跨越体区从上边界至下边界的类非互易隧穿现象。该研究揭示了非互易体态与反手性边缘态之间的内在关联，为设计理想体态-边界耦合器、分束器及多元应用提供了创新思路。

附：英文原文

Title: One-way bulk-boundary coupling in a two-dimensional antiferromagnetic photonic Dirac semimetal

Author: Ze-Qun Sun, Yan-Chen Zhou, Meng-Han Yu, Hua-Shan Lai, Cheng He, Yan-Feng Chen

Issue&Volume: 2025/11/18

Abstract: Recently discovered antichiral edge states, which are pinned to a pair of offset Dirac points with different degenerate energies, exhibit the same propagating direction along parallel boundaries. However, few studies focus on accompanying opposite bulk propagation in terms of energy conservation in nondissipative systems. Here, we fabricate a two-dimensional honeycomb-lattice antiferromagnetic photonic crystal to construct a photonic Dirac semimetal. Both nonreciprocal bulk states and antichiral edge states are observed in the vicinity of the Dirac point frequency in microwave experiments. Using a rhombus-shaped sample, we realize one-way bulk to boundary and boundary to bulk couplings. Furthermore, we demonstrate a nonreciprocal tunnelinglike phenomenon from the upper to the lower boundaries across the bulk region. Our results highlight the underlying relation between the nonreciprocal bulk and antichiral edge states, which may provide an ideal strategy to design perfect bulk-boundary couplers, splitters, and various other applications.

DOI: 10.1103/vz11-nn51

Source: https://journals.aps.org/pra/abstract/10.1103/vz11-nn51