Quantum Register Based on Individual Electronic and Nuclear Spin Qubits in Diamond

TLDR

The key challenge in experimental quantum information science is to identify isolated quantum mechanical systems with long coherence times that can be manipulated and coupled together in a scalable fashion. The study aims to create a controllable quantum register by coherently manipulating an individual electron spin and nearby nuclear spins. This is achieved by coherently manipulating the electron spin and nearby nuclear spins to form a controllable quantum register. The authors demonstrated room‑temperature initialization and arbitrary state transfer between electron and nuclear spin qubits, isolated nuclear spins during optical readout, coherent interactions with excellent coherence, establishing a scalable, optically coupled quantum register.

Abstract

The key challenge in experimental quantum information science is to identify isolated quantum mechanical systems with long coherence times that can be manipulated and coupled together in a scalable fashion. We describe the coherent manipulation of an individual electron spin and nearby individual nuclear spins to create a controllable quantum register. Using optical and microwave radiation to control an electron spin associated with the nitrogen vacancy (NV) color center in diamond, we demonstrated robust initialization of electron and nuclear spin quantum bits (qubits) and transfer of arbitrary quantum states between them at room temperature. Moreover, nuclear spin qubits could be well isolated from the electron spin, even during optical polarization and measurement of the electronic state. Finally, coherent interactions between individual nuclear spin qubits were observed and their excellent coherence properties were demonstrated. These registers can be used as a basis for scalable, optically coupled quantum information systems.