| Autor: |
Lin, Y. S., Wang, S. Y., Zhang, X., Feng, Y., Pan, Y. P., Ru, H., Zhu, J. J., Xiang, B. K., Liu, K., Zheng, C. L., Wei, L. Y., Wang, M. X., Liu, Z. K., Chen, L., Jiang, K., Guo, Y. F., Wang, Ziqiang, Wang, Y. H. |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
PhysRevX.13.011046 (2023) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevX.13.011046 |
| Popis: |
Vortices are topological defects of type-II superconductors in an external magnetic field. In a similar fashion to a quantum anomalous Hall insulator, quantum anomalous vortex (QAV) spontaneously nucleates due to orbital-and-spin exchange interaction between vortex core states and magnetic impurity moment, breaking time-reversal symmetry (TRS) of the vortex without an external field. Here, we used scanning superconducting quantum interference device microscopy (sSQUID) to search for its signatures in iron-chalcogenide superconductor Fe(Se,Te). Under zero magnetic field, we found a stochastic distribution of isolated anomalous vortices and antivortices with flux quanta $\Phi_0$. By applying a small local magnetic field under the coil of the nano-SQUID device, we observed hysteretic flipping of the vortices reminiscent of the switching of ferromagnetic domains, suggesting locally broken-TRS. We further showed vectorial rotation of a flux line linking a paired vortex-antivortex with the local field. These unique properties of the anomalous vortices satisfied the defining criteria of QAV. Our observation suggests a quantum vortex phase with spontaneous broken-TRS in a high-temperature superconductor. |
| Databáze: |
arXiv |
| Externí odkaz: |
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