Topology is a key ingredient driving the emergence of quantum devices. Topological field-effect transistor (TFET) has been proposed to outperform the conventional FET by replacing the ON state with topology-protected quantized conductance, while the OFF state remains the same normal insulating characteristics and hence bears similar drawbacks. Here, we demonstrate a proof-of-concept TFET having both ON and OFF quantized conductance, by switching between helical and chiral topological screw dislocation (SD) states in three-dimensional topological insulators. A pair of SDs are configured with one acting as channel and the other as gate controlled by local magnetic field. A reversible field-switching is achieved with the ON and OFF conductance of 2e2/h and e2/h, respectively, as shown by tight-binding quantum transport calculations. Furthermore, BaBiO3 is shown as a candidate material having the desired topological SD states, based on first-principles calculations. Our findings open a new route to high-fidelity topological quantum devices.
@article{arxiv.2211.11837,
title = {Topological field-effect transistor with quantized ON/OFF conductance of helical/chiral dislocation states},
author = {Xiaoyin Li and Feng Liu},
journal= {arXiv preprint arXiv:2211.11837},
year = {2023}
}