Absence of Nematic Instability in The Kagome Metal CsV₃Sb₅

Ever since the discovery of the charge density wave (CDW) transition in the kagome metal CsV₃Sb₅, the nature of its symmetry breaking is under intense debate. While evidence suggests that the rotational symmetry is already broken at the CDW transition temperature (T_CDW), an additional electronic nematic instability well below T_CDW was reported based on the diverging elastoresistivity coefficient in the anisotropic channel (m_E2g). Verifying the existence of a nematic transition below T_CDW is not only critical for establishing the correct description of the CDW order parameter, but also important for understanding the low-temperature superconductivity. Here, we report elastoresistivity measurements of CsV₃Sb₅ using three different techniques probing both isotropic and anisotropic symmetry channels. Contrary to previous reports, we find the anisotropic elastoresistivity coefficient m_E2g is temperature-independent except for a step jump at T_CDW. The absence of nematic fluctuations is further substantiated by measurements of the elastocaloric effect, which show no enhancement associated with nematic susceptibility. On the other hand, the symmetric elastoresistivity coefficient m_A1g increases below T_CDW, reaching a peak value of 90 at T^{<span style="font-size:10.8333px">*</span>}=20 K. Our results strongly indicate that the phase transition at T^*<span style="font-size:10.8333px"> </span>is not nematic in nature and the previously reported diverging elastoresistivity is due to the contamination from the A_1g channel.