Readout and control of an endofullerene electronic spin

Dinesh Pinto,Tim Dierker,Jörg Wrachtrup,Domenico Paone,René Wieczorek,Bastian Kern,Durga Dasari,Wolfgang Harneit,Amit Finkler,Klaus Kern,Aparajita Singha

doi:10.1038/s41467-020-20202-3

Abstract

Atomic spins for quantum technologies need to be individually addressed and positioned with nanoscale precision. C60 fullerene cages offer a robust packaging for atomic spins, while allowing in-situ physical positioning at the nanoscale. However, achieving single-spin level readout and control of endofullerenes has so far remained elusive. In this work, we demonstrate electron paramagnetic resonance on an encapsulated nitrogen spin (14N@C60) within a C60 matrix using a single near-surface nitrogen vacancy (NV) center in diamond at 4.7 K. Exploiting the strong magnetic dipolar interaction between the NV and endofullerene electronic spins, we demonstrate radio-frequency pulse controlled Rabi oscillations and measure spin-echos on an encapsulated spin. Modeling the results using second-order perturbation theory reveals an enhanced hyperfine interaction and zero-field splitting, possibly caused by surface adsorption on diamond. These results demonstrate the first step towards controlling single endofullerenes, and possibly building large-scale endofullerene quantum machines, which can be scaled using standard positioning or self-assembly methods.

Highlights

Atomic spins for quantum technologies need to be individually addressed and positioned with nanoscale precision
The nitrogen vacancy (NV) center is ubiquitous as a quantum sensor whose robust solid-state packaging and unique energy level structure make it ideal as a noninvasive local magnetic field probe[13,14]
The optical collection efficiency of the NV centers was enhanced by guiding the emitted light using tapered nanowaveguides structured directly onto the diamond substrate[15]

Summary

Introduction

Atomic spins for quantum technologies need to be individually addressed and positioned with nanoscale precision. Modeling the results using second-order perturbation theory reveals an enhanced hyperfine interaction and zero-field splitting, possibly caused by surface adsorption on diamond These results demonstrate the first step towards controlling single endofullerenes, and possibly building large-scale endofullerene quantum machines, which can be scaled using standard positioning or self-assembly methods. The experiment is performed at low magnetic fields (B ≈ 10 mT), leading to second-order corrections to the N@C60 energy-level scheme of order A2/(γefB) ≈ 1 MHz, where A is the N@C60 hyperfine constant and γeB is the electronic Zeeman shift. We utilize the dipolar interaction of the N@C60 electronic spin with a local readout sensor to demonstrate single-spin level endofullerene spin readout and control

Methods

Results

Conclusion