2026/07/16 by Xiaoran Yang, Yutong Li, Chunyi Li +5
#cond-mat.supr-con #cond-mat.str-el
The kagome metal CsV3Sb5 hosts an intriguing interplay between charge-density-wave (CDW) order and superconductivity that is highly sensitive to lattice distortions. However, determining the specific roles of the in-plane (A1g,1) and out-of-plane (A1g,2) symmetric strain channels has been hindered by their intrinsic mixing in conventional piezo-based experiments. Here, we combine in-plane uniaxial strain with direct c-axis compression to independently access and disentangle these symmetry-resolved responses in CsV3Sb5. We reveal that c-axis compression drives a massive, linear enhancement of the superconducting transition temperature (Tc) alongside a suppression of T\rm CDW. The tuning efficiency of this out-of-plane deformation acts with an opposite sign and far exceeds that of in-plane strain, demonstrating that c-axis lattice control dictates the phase competition. Furthermore, by isolating the pure elastoresistivity coefficients, we find that the out-of-plane cross-coupling coefficient (m13) is comparable in magnitude but opposite in sign to the in-plane response (m11+m12). Unlike the sharply peaked in-plane response, m13 exhibits a distinct, order-parameter-like onset across the CDW transition. Our results establish that out-of-plane lattice control plays a dominant role in tuning the intertwined states in CsV3Sb5 and provide a general pathway for resolving strain-coupled electronic responses in layered quantum materials.