Probing the Hall anomaly and electronic structure in kagome metal RbV₃Sb₅ under hydrostatic pressure

Kagome metals AV ${ }_3$ Sb ${ }_5$ (A = K, Rb, Cs) are renowned for their intricate electronic band structures, providing a rich platform for investigating topological states and electronic correlations. Within the AV ${ }_3$ Sb ${ }_5$ family, the detailed electronic structures of CsV ${ }_3$ Sb ${ }_5$ and KV ${ }_3$ Sb ${ }_5$ have been well established, both in their charge-density-wave (CDW) phase or in the pristine metallic phase. Yet, the electronic structure of RbV ${ }_3$ Sb ${ }_5$ remains under-explored. In this manuscript, we present a detailed study of the electronic structure of RbV ${ }_3$ Sb ${ }_5$ revealed by Shubnikov-de Haas oscillation in both the CDW phase (9 kbar), and where the CDW phase is just fully suppressed (22 kbar). The greatly simplified Fast Fourier transform spectrum at 22 kbar implies the absence of Fermi surface reconstruction caused by the CDW order, and the observation of enhanced quasi-particle effective masses near the CDW boundary indicates enhanced quantum fluctuations. Furthermore, the mobilities of charge carriers from the CDW phase to the metallic pristine phase are studied using mobility spectrum analysis (MSA). Our MSA results reveal that high-mobility carriers ( $\approx 10,000$ cm ${ }^2$ /Vs) coexist with the non-monotonic Hall effect near-zero field at 9 kbar. As the pressure increases to 22 kbar and 30 kbar, this non-monotonic feature is suppressed, concomitant with the disappearance of the high-mobility carriers. By summarizing the MSA results across the AV ${ }_3$ Sb ${ }_5$ family, we observed that the superconducting behavior appears to be positively correlated with carrier mobility and number. This correlation suggests that high-mobility carriers may play a crucial role in the underlying superconducting pairing mechanism.