The authors study CsV3Sb5 by nuclear quadrupole resonance. At ambient pressure, there are two superconducting gaps with line nodes in the smaller one. For pressures above Pc ~ 1.85 GPa, where the charge-density wave phase is completely suppressed, they observe fully-gapped superconductivity with broken rotational symmetry.
- X. Y. Feng
- Z. Zhao
- Guo-qing Zheng