Electronic Properties in Kagome Superconductors AV3Sb5(A=K, Rb, Cs) and CsCr3Sb5.

Abstract

The materials with Kagome lattice have evoked tremendous interest in communities of condensed matter physics and material science due to their fascinating features, such as electronic correlation effects, topological properties, unconventional superconductivity, and rich charge orders. Among them, AV₃Sb₅ (A = K, Rb, Cs) system is thoroughly investigated since its fabrication in 2019, and a rich phase diagram of quantum states including the charge density wave (CDW) order, electronic nematic phase, conventional and unconventional superconducting phases is obtained under different temperatures and external pressures. Here, the recent progress is reviewed on the electronic properties in the AV₃Sb₅ system. Several kinds of Van Hove singularities emerge near the Fermi surface, engendering two rival orders of CDW and superconductivity due to the Fermi instability. The relationship between the pressure and superconducting transition temperature is summarized by enumerating the superconducting properties of different samples. Moreover, the possible unconventional superconductivity accompanied by charming magnetic orders in a new material, CsCr₃Sb₅, which is obtained by completely replacing V atoms with Cr atoms, is addressed under high pressure. Finally, a perspective on the realization of unconventional superconductivity is proposed in the ambient atmosphere to lower the threshold of superconductivity study in this region.