@article{kiphart_investigations_2021,
title = {Investigations of proximity-induced superconductivity in the topological insulator Bi2Te3 by microRaman spectroscopy},
author = {D Kiphart and Y Harkavyi and K Balin and J Szade and Bogusław Mróz and P Kuświk and S Jurga and M Wiesner},
url = {https://www.nature.com/articles/s41598-021-02475-w},
doi = {10.1038/s41598-021-02475-w},
issn = {2045-2322},
year = {2021},
date = {2021-11-26},
journal = {Scientific Reports},
volume = {11},
number = {1},
pages = {22980},
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 YBa2Cu3O7-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 textgreater Tc that converts into a superconducting state with a reduced gap for T textless Tc. 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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{TRZASKOWSKA2021106526,
title = {Dispersion of the surface phonons in semiconductor/topological insulator Si/Bi2Te3 heterostructure studied by high resolution Brillouin spectroscopy},
author = {Aleksandra Trzaskowska and Sławomir Mielcarek and M Wiesner and F Lombardi and Bogusław Mróz},
url = {https://www.sciencedirect.com/science/article/pii/S0041624X21001554},
doi = {https://doi.org/10.1016/j.ultras.2021.106526},
year = {2021},
date = {2021-07-21},
journal = {Ultrasonics},
volume = {117},
pages = {106526},
abstract = {The dynamics and dispersion of surface phonons in heterostructure semiconductor/ topological insulator Si/Bi2Te3 was investigated using high resolution Brillouin light scattering method in the GHz frequency range. Both Rayleigh and Sezawa surface acoustic waves have been observed for wave vectors ranging from 0.006 to 0.023 nm−1. Anomaly in dispersion relations ω(q) for both surface waves were detected for the wave vector q = 0.016 nm−1. The finite element method (FEM) was used to simulate the observed shapes of ω(q) and to find the deformation profiles of surface acoustic waves. We attribute the observed changes to the coupling between low energy electrons and surface phonons. The coupling between helical Dirac states and surface phonons is discussed in the frame of accessible theoretical models.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}