Topological field-effect transistor with quantized ON/OFF conductance of helical/chiral dislocation states

TL;DR

This paper demonstrates a topological field-effect transistor with both ON and OFF states exhibiting quantized conductance, achieved by switching between helical and chiral dislocation states in topological insulators, promising high-fidelity quantum devices.

Contribution

It introduces a novel TFET design with both states having quantized conductance, utilizing topological dislocation states in 3D topological insulators, supported by theoretical calculations.

Findings

Reversible switching between helical and chiral dislocation states with quantized conductance.

Achieved ON/OFF conductance of 2e^2/h and e^2/h respectively.

BaBiO3 identified as a candidate material for these topological states.

Abstract

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 $2e^2/h$ and $e^2/h$, respectively, as shown by tight-binding quantum transport calculations. Furthermore, BaBiO$_3$ 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.