Investigations of proximity-induced superconductivity in the topological insulator Bi₂Te₃ by microRaman spectroscopy.

ABSTRACT: We used the topological insulator (TI) Bi₂Te₃ and a high-temperature superconductor (HTSC) hybrid device for investigations of proximity-induced superconductivity (PS) in the TI. Application of the superconductor YBa₂Cu₃O_7-δ (YBCO) enabled us to access higher temperature and energy scales for this phenomenon. The HTSC in the hybrid device exhibits emergence of a pseudogap state for T > T_c that converts into a superconducting state with a reduced gap for T < T_c. The conversion process has been reflected in Raman spectra collected from the TI. Complementary charge transport experiments revealed emergence of the proximity-induced superconducting gap in the TI and the reduced superconducting gap in the HTSC, but no signature of the pseudogap. This allowed us to conclude that Raman spectroscopy reveals formation of the pseudogap state but cannot distinguish the proximity-induced superconducting state in the TI from the superconducting state in the HTSC characterised by the reduced gap. Results of our experiments have shown that Raman spectroscopy is a complementary technique to classic charge transport experiments and is a powerful tool for investigation of the proximity-induced superconductivity in the Bi₂Te₃.

SUBMITTER: Kiphart D 

PROVIDER: S-EPMC8626455 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature