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Momentum space toroidal moment in a photonic metamaterial.

ABSTRACT: 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.

SUBMITTER: Yang B

PROVIDER: S-EPMC7979886 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Momentum space toroidal moment in a photonic metamaterial.

Yang Biao B Bi Yangang Y Zhang Rui-Xing RX Zhang Ruo-Yang RY You Oubo O Zhu Zhihong Z Feng Jing J Sun Hongbo H Chan C T CT Liu Chao-Xing CX Zhang Shuang S

Nature communications 20210319 1

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 ...[more]

PMID: 33741969

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