Recently, the Metamaterials and Optical Fiber Devices Research Group of the School of Physics and Optoelectronic Engineering at Harbin Engineering University has experimentally observed the angle-dependent reconstruction of Fermi arcs by utilizing continuously twisted Weyl metacrystals. This work has revealed the unique phenomenon of aperiodic scattering of Fermi arcs, making it possible to continuously manipulate Fermi arcs and providing a referable approach for the design of novel devices and information modulation methods. The research results, titled "Twisted photonic Weyl meta-crystals and aperiodic Fermi arc scattering", were published online on March 18th, 2024 in the internationally authoritative journal Nature Communications.
Fermi arcs in twisted Weyl metacrystals.
The Fermi surface in metals is a boundary between the occupied and unoccupied energy states. The Fermi surface usually has closed contours and forms shapes such as spheres and ellipsoids. The electrons located on the Fermi surface govern many properties of materials, such as electrical and thermal conductivity, and optical properties. Weyl metacrystals possess the characteristics of topological surface states. The Fermi surface formed by these surface states is composed of discontinuous line segments, known as Fermi arcs, which are important features for revealing the topological properties of the structure. Topological surface states are a concept in quantum physics that describes the special electronic states on the surface of materials and have potential application value in fields such as materials science and quantum computing.
Fermi arcs in periodic and ordered topological structures have been widely studied, while it is still rather difficult to observe Fermi arcs in aperiodic and complex structures. This work achieved a breakthrough in the experimental observation of aperiodic Fermi arcs and pointed out that the phase Riemann surface is an important reason for the aperiodic scattering of Fermi arcs. Through continuously twisting the Weyl metacrystals, aperiodic structures emerged, revealing the scattering characteristics of Fermi arcs on their interfaces. This work helps to understand the physical phenomena in aperiodic systems and also expands people's understanding of solid-state physics and crystallography.
This paper was jointly completed by Harbin Engineering University, the National University of Defense Technology, Tongji University, and Hunan University. Wang Yiyuan, a 2020 doctoral student from the School of Physics and Optoelectronic Engineering at Harbin Engineering University, is one of the co-first authors of the paper, and Professor Shi Jinhui, the supervisor, is one of the co-corresponding authors. This work was guided by Professor Zhang Shuang from the University of Hong Kong and supported by the Basic Research Enhancement Program of the university and the National Natural Science Foundation of China.
In recent years, the Metamaterials and Optical Fiber Devices Research Group has been deeply engaged in basic research. Taking Harbin Engineering University as the first or corresponding author's institution, it has published more than 150 high-level SCI papers, including international high-level academic journals such as Science Advances, National Science Review, Physical Review Letters, and Laser & Photonics Reviews. The research group has continuously accumulated in the direction of topological photonics, explored novel topological optical devices, and achieved novel three-dimensional topological phenomena by using classical circuit networks, providing new methods for exploring other physical phenomena such as topological phase transitions, nonlinear effects, high-dimensional physical states, and open quantum systems.
Nature Communications was founded in 2010. It is a comprehensive scientific journal covering all academic fields under the Nature brand. The journal focuses on influential research results in various scientific fields and is highly recognized by scholars both at home and abroad. It is a top journal in Zone 1 of the Chinese Academy of Sciences, and its impact factor in 2023 was 16.6.
