Momentum space toroidal moment in a photonic metamaterial

Biao Yang, Yangang Bi, Rui Xing Zhang, Ruo Yang Zhang, Oubo You, Zhihong Zhu, Jing Feng, Hongbo Sun, C. T. Chan, Chao Xing Liu, Shuang Zhang

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Berry curvature, the counterpart of the magnetic field in the momentum space, plays a vital role in the transport of electrons in condensed matter physics. It also lays the foundation for the emerging field of topological physics. In the three-dimensional systems, much attention has been paid to Weyl points, which serve as sources and drains of Berry curvature. Here, we demonstrate a toroidal moment of Berry curvature with flux approaching to π in judiciously engineered metamaterials. The Berry curvature exhibits a vortex-like configuration without any source and drain in the momentum space. Experimentally, the presence of Berry curvature toroid is confirmed by the observation of conical-frustum shaped domain-wall states at the interfaces formed by two metamaterials with opposite toroidal moments.

Original languageEnglish (US)
Article number1784
JournalNature communications
Issue number1
StatePublished - Dec 1 2021

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology
  • General Physics and Astronomy


Dive into the research topics of 'Momentum space toroidal moment in a photonic metamaterial'. Together they form a unique fingerprint.

Cite this