Here we visualize the trapping of topological surface states in the circular n-p junctions on the top surface of the 7-quintuple-layer three dimensional (3D) topological insulator (TI) Sb2Te3 epitaxial films. As shown by spatially- and field-dependent tunneling spectra, these trapped resonances show field-induced splittings between the degenerate time-reversal-symmetric states at zero magnetic field. These behaviors are attributed unambiguously to Berry-phase switch by comparing the experimental data with both numerical and semi-classical simulations. The successful electrostatic trapping of topological surface states in epitaxial films and the observation of Berry-phase switch provide a rich platform of exploiting new ideas for TI-based quantum devices.
@article{arxiv.2203.01759,
title = {Berry-phase switch in electrostatically-confined topological surface states},
author = {Jun Zhang and Ye-ping Jiang and Xu-Cun Ma and Qi-Kun Xue},
journal= {arXiv preprint arXiv:2203.01759},
year = {2022}
}