Unconventional transformation of spin Dirac phase across a topological quantum phase transition
Abstract
The topology of a topological material can be encoded in its surface states. These surface states can only be removed by a bulk topological quantum phase transition into a trivial phase. Here we use photoemission spectroscopy to image the formation of protected surface states in a topological insulator as we chemically tune the system through a topological transition. Surprisingly, we discover an exotic spin-momentum locked, gapped surface state in the trivial phase that shares many important properties with the actual topological surface state in anticipation of the change of topology. Using a spin-resolved measurement, we show that apart from a surface band-gap these states develop spin textures similar to the topological surface states well-before the transition. Our results offer a general paradigm for understanding how surface states in topological phases arise and are suggestive for future realizing Weyl arcs, condensed matter supersymmetry and other fascinating phenomena in the vicinity of topological quantum criticality.
Keywords
Cite
@article{arxiv.1503.07765,
title = {Unconventional transformation of spin Dirac phase across a topological quantum phase transition},
author = {Su-Yang Xu and Madhab Neupane and Ilya Belopolski and Chang Liu and Nasser Alidoust and Guang Bian and Shuang Jia and Gabriel Landolt and Bartosz Slomski and J. Hugo Dil and Pavel P. Shibayev and Susmita Basak and Tay-Rong Chang and Horng-Tay Jeng and Robert J. Cava and Hsin Lin and Arun Bansil and M. Zahid Hasan},
journal= {arXiv preprint arXiv:1503.07765},
year = {2015}
}
Comments
20 pages, 5 Figures, Related papers at http://physics.princeton.edu/zahidhasangroup/index.html, Accepted for publication in Nature Commun.(2015)