Pressure suppresses the density wave order in kagome metal LuNb$_6$Sn$_6$

Abstract

Dancing tins pair up, But compressing the framework Thwarts the displacements. The density waves that develop in kagome metals ScV$_{6}$Sn$_{6}$ and LuNb$_{6}$Sn$_{6}$ at low temperature appear to arise from under-filled atomic columns within a V-Sn or Nb-Sn scaffolding. Compressing this network with applied pressure in ScV$_{6}$Sn$_{6}$ suppressed the structural transition temperature by constraining atomic rattling and inhibiting the shifts that define the structural modulation. We predicted that the density wave transition in LuNb$_{6}$Sn$_{6}$ at 68 K would be suppressed by pressure as well. In this brief study, we examine the pressure dependence of the density wave transition by measuring resistance vs temperature up to 2.26 GPa. We found the transition temperature is smoothly depressed and disappears around 1.9 GPa. This result not only addresses our prediction, but strengthens the rattling chains origin of structural instabilities in the HfFe$_{6}$Ge$_{6}$-type kagome metals.