Peculiar properties of -chain-based superconductors

Abstract

(A = K, Rb, Cs) are the unique Cr-based ambient-pressure superconductors discovered in 2015. The new superconducting family are structurally characterised by quasi one-dimensional (Q1D) [() double-walled subnanotubes. Peculiar properties have been revealed, which mostly point to unconventional superconductivity. In this contribution, we first describe how the superconductors were discovered. Then we overview recent progress on the crystal structure, electronic structures, theoretical models and physical properties in . Some new experimental results are included. Finally, we conclude by addressing the related open questions in this emerging subfield of superconductivity.

Keywords:

• Cr-based superconductors
• unconventional superconductivity
• quasi-one dimensionality

Acknowledgements

We thank Z. A. Xu, J. Y. Liu, H. Q. Yuan, Chao Cao, F. L. Ning, T. Imai, Guo-qing Zheng, L. L. Sun, and Z. W. Zhu for fruitful collaborations. Thanks are also due to D. F. Agterberg, F. C. Zhang, Y. Zhou, J. H. Dai, F. Yang, and J. P. Hu for helpful discussions.

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 11674281); National Key R & D Program of the MOST of China [grant number 2016YFA0300202]; the Fundamental Research Funds for the Central Universities of China.