Coherent state transfer between an electron- and nuclear spin in 15N@C60

TL;DR

This paper demonstrates a method for transferring quantum information between electron and nuclear spins in 15N@C60, enabling controlled interactions and long coherence times for quantum computing applications.

Contribution

It introduces a hybrid electron-nuclear spin transfer scheme in 15N@C60 with high fidelity, enhancing control over qubit interactions and coherence.

Findings

Achieved 88% fidelity in state transfer

Measured nuclear spin coherence lifetime over 100 ms

Enabled controllable dipolar interactions via spin transfer

Abstract

Electron spin qubits in molecular systems offer high reproducibility and the ability to self assemble into larger architectures. However, interactions between neighbouring qubits are 'always-on' and although the electron spin coherence times can be several hundred microseconds, these are still much shorter than typical times for nuclear spins. Here we implement an electron-nuclear hybrid scheme which uses coherent transfer between electron and nuclear spin degrees of freedom in order to both controllably turn on/off dipolar interactions between neighbouring spins and benefit from the long nuclear spin decoherence times (T2n). We transfer qubit states between the electron and 15N nuclear spin in 15N@C60 with a two-way process fidelity of 88%, using a series of tuned microwave and radiofrequency pulses and measure a nuclear spin coherence lifetime of over 100 ms.