ABSTRACT

In kagome metal CsV3Sb5, multiple intertwined orders are accompanied by both electronic and structural instabilities. These exotic orders have attracted much recent attention, but their origins remain elusive. The newly discovered CsTi3Bi5 is a Ti-based kagome metal to parallel CsV3Sb5. Here, we report angle-resolved photoemission experiments and first-principles calculations on pristine and Cs-doped CsTi3Bi5 samples. Our results reveal that the van Hove singularity (vHS) in CsTi3Bi5 can be tuned in a large energy range without structural instability, different from that in CsV3Sb5. As such, CsTi3Bi5 provides a complementary platform to disentangle and investigate the electronic instability with a tunable vHS in kagome metals.

DOI:https://doi.org/10.1103/PhysRevLett.131.026701