Strain-sensitive superconductivity in the kagome metals KV3Sb5 and Cs V3Sb5 probed by point-contact spectroscopy

Lichang Yin, Dongting Zhang, Chufan Chen, Ge Ye, Fanghang Yu, Brenden R. Ortiz, Shuaishuai Luo, Weiyin Duan, Hang Su, Jianjun Ying, Stephen D. Wilson, Xianhui Chen, Huiqiu Yuan, Yu Song, Xin Lu

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

The kagome lattice is host to flat bands, topological electronic structures, Van Hove singularities, and diverse electronic instabilities, providing an ideal platform for realizing highly tunable electronic states. Here, we report soft and mechanical point-contact spectroscopy (SPCS and MPCS) studies of the kagome superconductors KV3Sb5 and CsV3Sb5. Compared to the superconducting transition temperature Tc from specific heat and electrical resistance measurements, significantly enhanced values of Tc are observed via the zero-bias conductance of SPCS, which become further enhanced in MPCS measurements. While the differential conductance curves from SPCS can be described by a two-gap s-wave model, a single s-wave gap reasonably captures the MPCS data, likely due to a diminishing spectral weight of the other gap. The enhanced superconductivity probably arises from local strain caused by the point contact, which also leads to two-gap or single-gap behaviors observed in different point contacts. Our results demonstrate highly strain-sensitive superconductivity in kagome metals CsV3Sb5 and KV3Sb5, which may be harnessed in the manipulation of possible Majorana zero modes.

Original languageEnglish
Article number174507
JournalPhysical Review B
Volume104
Issue number17
DOIs
StatePublished - Nov 1 2021
Externally publishedYes

Fingerprint

Dive into the research topics of 'Strain-sensitive superconductivity in the kagome metals KV3Sb5 and Cs V3Sb5 probed by point-contact spectroscopy'. Together they form a unique fingerprint.

Cite this