Entanglement in a solid-state spin ensemble

Abstract

Spin ensembles, such as those used in liquid-state nuclear magnetic resonance, have been important for the development of quantum control methods. However, these demonstrations contained no entanglement, which is essential for a quantum information processor. This study reports the on-demand generation of entanglement between an ensemble of electron and nuclear spins in phosphorus-doped silicon, simultaneously creating 1010 spin pairs.