Landau-Zener tunneling of a single Tb3+ magnetic moment allowing the electronic read-out of a nuclear spin

TL;DR

This paper demonstrates the use of a carbon nanotube quantum dot device to achieve single-shot read-out of a Terbium nuclear spin via Landau-Zener tunneling, advancing quantum control of nuclear spins.

Contribution

It introduces a method to detect and manipulate a single nuclear spin in a TbPc2 molecule using Landau-Zener tunneling in a nanotube device, with experimental validation.

Findings

Successful single-shot read-out of Terbium nuclear spin.

Linear increase of tunnel splitting with transverse field.

Good agreement of tunneling probability with Landau-Zener theory.

Abstract

A multi-terminal device based on a carbon nanotube quantum dot was used at very low tem- perature to probe a single electronic and nuclear spin embedded in a bis-phthalocyanine Terbium (III) complex (TbPc2). A spin-valve signature with large conductance jumps was found when two molecules were strongly coupled to the nanotube. The application of a transverse field separated the magnetic signal of both molecules and enabled single-shot read-out of the Terbium nuclear spin. The Landau-Zener (LZ) quantum tunneling probability was studied as a function of field sweep rate, establishing a good agreement with the LZ equation and yielding the tunnel splitting \Delta. It was found that ? increased linearly as a function of the transverse field. These studies are an essential prerequisite for the coherent manipulation of a single nuclear spin in TbPc2.