Experimental Observation of Tensor Monopoles with a Superconducting Qudit
Abstract
Monopoles play a center role in gauge theories and topological matter. There are two fundamental types of monopoles in physics: vector monopoles and tensor monopoles. Examples of vector monopoles include the Dirac monopole in 3D and Yang monopole in 5D, which have been extensively studied and observed in condensed matter or artificial systems. However, tensor monopoles are less studied, and their observation has not been reported. Here we experimentally construct a tunable spin-1 Hamiltonian to generate a tensor monopole and then measure its unique features with superconducting quantum circuits. The energy structure of a 4D Weyl-like Hamiltonian with three-fold degenerate points acting as tensor monopoles is imaged. Through quantum-metric measurements, we report the first experiment that measures the Dixmier-Douady invariant, the topological charge of the tensor monopole. Moreover, we observe topological phase transitions characterized by the topological Dixmier-Douady invariant, rather than the Chern numbers as used for conventional monopoles in odd-dimensional spaces.
Keywords
Cite
@article{arxiv.2006.11770,
title = {Experimental Observation of Tensor Monopoles with a Superconducting Qudit},
author = {Xinsheng Tan and Dan-Wei Zhang and Wen Zheng and Xiaopei Yang and Shuqing Song and Zhikun Han and Yuqian Dong and Zhimin Wang and Dong Lan and Hui Yan and Shi-Liang Zhu and Yang Yu},
journal= {arXiv preprint arXiv:2006.11770},
year = {2021}
}
Comments
6+6 pages, 4+4 figures; version accepted for publication in PRL