  Recently discovered Z2 topological kagome metals AV3Sb5 (A = K, Rb, and Cs)
exhibit intriguing transport anomalies and novel superconducting paring states,
providing a versatile platform for studying interplay between electron
correlation and quantum orders. Here we directly visualise how temperature
drives band renormalization and Lifshitz transition in RbV3Sb5 using
angle-resolved photoemission spectroscopy, pointing to the key role of tuning
van Hove singularities to the Fermi energy in mechanisms of both CDW and
superconducting orders. Multiple singularities with different energies and
orbital characters could induce various ordering phases, including
superconductivity if cooperating with matching bosons. Considering the
existence of the non-trivial topological Dirac surface states at the
time-reversal-invariant momentum points, they may also provide a promising
route to realize zero energy modes related to Majorana fermions. Our findings
are significant in understanding abundant transport behaviors and quantum
phases in these kagome superconductors.
