Low-temperature magnetic phase in novel Kagome superconductor RbV₃Sb₅

We present the low-temperature phase diagram as inferred by microscopic nuclear magnetic resonance  (NMR) measurements in a recently discovered material belonging to the class of Kagome superconductors [1], namely RbV₃Sb₅. This class of materials shows a Charge-Density Wave (CDW) phase transition at a temperature T_CDW ≅ 80÷103 K [2], related to a 2×2×2 structural modulation.

Furthermore, they are one of the first examples of 2D superconductivity in a Kagome model, with superconducting temperature T_c ≅ 1÷2.4 K.

Thus this class of materials provides a very challenging platform to explore the interplay of superconductivity and exotic electronic correlations due to the frustrated geometry of the crystalline structure.

Here we present NMR measurements, that provides a powerful method to explore electronic correlations and their effect in materials with frustrated geometry, on an RbV₃Sb₅ single crystal.  Furthermore, we will discuss the implications of first-principles DFT calculations on the interpretation of our NMR findings. 

Work at Brown was supported in part by the the National Science Foundation grant No. DMR-1905532.

[1] B. R. Ortiz et al., Phys. Rev. Mat. 3, 094407 (2019).

[2] Q. Yin et al., Chin. Phys. Lett. 38, 037403 (2021).