Preservation of Topological Surface States in Millimeter-Scale Transferred Membranes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38758657.
- Also identified by DOI 10.1021/acs.nanolett.4c00008 and PMC identifier 11212057.
- Licence recorded as CC BY-NC-ND.
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Abstract
Ultrathin topological insulator membranes are building blocks of exotic quantum matter. However, traditional epitaxy of these materials does not facilitate stacking in arbitrary orders, while mechanical exfoliation from bulk crystals is also challenging due to the non-negligible interlayer coupling therein. Here we liberate millimeter-scale films of the topological insulator Bi<sub>2</sub>Se<sub>3</sub>, grown by molecular beam epitaxy, down to 3 quintuple layers. We characterize the preservation of the topological surface states and quantum well states in transferred Bi<sub>2</sub>Se<sub>3</sub> films using angle-resolved photoemission spectroscopy. Leveraging the photon-energy-dependent surface sensitivity, the photoemission spectra taken with 6 and 21.2 eV photons reveal a transfer-induced migration of the topological surface states from the top to the inner layers. By establishing clear electronic structures of the transferred films and unveiling the wave function relocation of the topological surface states, our work lays the physics foundation crucial for the future fabrication of artificially stacked topological materials with single-layer precision.