Sensing coherent dynamics of electronic spin clusters in solids

TL;DR

This paper demonstrates the coherent quantum dynamics of strongly interacting electronic spins in a solid-state system at room temperature, using a nitrogen vacancy center in diamond to observe and control spin interactions.

Contribution

It provides the first detailed spectroscopy and control of coupled electronic spins in a solid at room temperature, advancing quantum information processing.

Findings

Observation of coherent flip-flop dynamics between electron spins

Quantification of NV-electron and electron-electron couplings

Demonstration of polarization transfer between NV and electron spins

Abstract

We present experimental observations and a study of quantum dynamics of strongly interacting electronic spins, at room temperature in the solid state. In a diamond substrate, a single nitrogen vacancy (NV) center coherently interacts with two adjacent S = 1/2 dark electron spins. We quantify NV-electron and electron-electron couplings via detailed spectroscopy, with good agreement to a model of strongly interacting spins. The electron-electron coupling enables an observation of coherent flip-flop dynamics between electronic spins in the solid state, which occur conditionally on the state of the NV. Finally, as a demonstration of coherent control, we selectively couple and transfer polarization between the NV and the pair of electron spins. These results demonstrate a key step towards full quantum control of electronic spin registers in room temperature solids.