Charge-dependent surface states of bismuth

We utilize angle-resolved photoemission spectroscopy (ARPES) to carefully investigate the electronic structures on different surfaces of Bismuth, a representative of higher-order topological insulators. Our study unveils interesting associations between the surface properties of bismuth and the electron charge configurations on the surface. Notably, we observe that the presence or absence of the gapless surface states on bismuth surfaces is significantly influenced by these charge arrangements. Our finding is also linked to the Z2 topology of bismuth and suggests possibilities for studying obstructed surface states in a broader range of topological materials.