Tunable spin-polaron state in a singly clamped semiconducting carbon nanotube

TL;DR

This paper demonstrates the theoretical possibility of creating a tunable, localized, spin-polarized polaronic state in a semiconducting carbon nanotube by electrostatic means, with potential for quantum spin manipulation.

Contribution

It extends previous models to show how a local magnetic field from a ferromagnetic substrate can induce a tunable spin-polarized polaron in a CNT.

Findings

Electrostatically controllable spin-polarized polaronic state can be localized at the CNT bending end.

Low-temperature manipulation and detection of the spin state are feasible.

The model generalizes prior approaches to include substrate-induced exchange interactions.

Abstract

We consider a semiconducting carbon nanotube (CNT) laying on a ferromagnetic insulating sub-strate with one end depassing the substrate and suspended over a metallic gate. We assume that the polarised substrate induces an exchange interaction acting as a local magnetic field for the electrons in the non-suspended CNT side. Generalizing the approach of I. Snyman and Yu.V. Nazarov [Phys. Rev. Lett. 108, 076805 (2012)] we show that one can generate electrostatically a tun-able spin-polarized polaronic state localized at the bending end of the CNT. We argue that at low temperatures manipulation and detection of the localised quantum spin state is possible.