Bends In Nanotubes Allow Electric Spin Control and Coupling

TL;DR

This paper demonstrates how bends in carbon nanotubes enable electrical control and coupling of confined spins, facilitating quantum gate operations through device geometry and capacitive interactions.

Contribution

It introduces a method to control and couple spins in nanotubes via bends, enabling universal quantum gates with electrical manipulation and inter-tube interactions.

Findings

Bends enable electrical control of confined spins.

Capacitive coupling along bends allows spin-spin interactions.

Device geometries support universal quantum gate operations.

Abstract

We investigate combined effects of spin-orbit coupling and magnetic field in carbon nanotubes containing one or more bends along their length. We show how bends can be used to provide electrical control of confined spins, while spins confined in straight segments remain insensitive to electric fields. Device geometries that allow general rotation of single spins are presented and analyzed. In addition, capacitive coupling along bends provides coherent spin-spin interaction, including between otherwise disconnected nanotubes, completing a universal set of one- and two-qubit gates.