A transition-metal qubit in diamond with all-optical control and millisecond quantum memory

2026/07/02 by I. M. Morris, T. Alberth, L. Crooks +6 · 1 voice
Physics and Astronomy · #quant-ph #cond-mat.other #physics.atom-ph

paper · pdf

Abstract

Quantum networks require qubits that combine efficient optical access, coherent control, and long-lived quantum memory, but realizing all three in one scalable platform remains a central bottleneck. Diamond color centers are leading candidates, yet widely studied defects retain tradeoffs among these capabilities. Here, we show that transition-metal defects in diamond provide a distinct route beyond these platforms by combining spin-orbit protected ground-state coherence, all-optical control, and near-infrared emission. Using a single nickel-vacancy (NiV^-), we demonstrate an all-optically controlled diamond spin qubit with coherence exceeding one millisecond at 1.65 K, compatible with compact closed-cycle cryogenics. We implement Raman Rabi oscillations and Ramsey interferometry and use all-optical dynamical decoupling to extend coherence from T₂^* = 371 ns to T₂^CPMG-4 = 1.27 ms, establishing NiV^- as a deployable diamond spin-photon interface.

Citations

• Lifetime-Limited and Tunable Emission from Single Charge-Stabilized Nickel Vacancy Centers in Diamond
• Microwave Control of the Tin-Vacancy Spin Qubit in Diamond with a Superconducting Waveguide
• Realization of a multi-node quantum network of remote solid-state qubits
• Ab initio magneto-optical spectrum of Group-IV -- Vacancy color centers in diamond
• Strain engineering of the silicon-vacancy center in diamond
• Silicon-Vacancy Spin Qubit in Diamond: A Quantum Memory Exceeding 10 ms with Single-Shot State Readout
• All-optical control of the silicon-vacancy spin in diamond at millikelvin temperatures
• Tin-Vacancy Quantum Emitters in Diamond
• Observation of an environmentally insensitive solid state spin defect in diamond
• The neutral silicon-vacancy center in diamond: spin polarization and lifetimes
• Deterministic enhancement of coherent photon generation from a nitrogen-vacancy center in ultrapure diamond
• Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km
• Electron-phonon processes of the silicon-vacancy centre in diamond
• All-optical initialization, readout, and coherent preparation of single silicon-vacancy spins in diamond
• All-optical formation of coherent dark states of silicon-vacancy spins in diamond
• Freely Scalable Quantum Technologies Using Cells of 5-to-50 Qubits with Very Lossy and Noisy Photonic Links
• A quantum network of clocks
• The electronic structure of the silicon vacancy color center in diamond
• Low Temperature Studies of Charge Dynamics of Nitrogen-Vacancy Defect in Diamond
• Heralded entanglement between solid-state qubits separated by 3 meters
• Large Scale Modular Quantum Computer Architecture with Atomic Memory and Photonic Interconnects
• Photophysics of single silicon vacancy centers in diamond: implications for single photon emission
• Coupling of Nitrogen-Vacancy Centers to Photonic Crystal Cavities in Monocrystalline Diamond
• Longer-Baseline Telescopes Using Quantum Repeaters
• Universal dynamical decoupling of a single solid-state spin from a spin bath
• The Quantum Internet
• How to enhance dephasing time in superconducting qubits
• Stark shift control of single optical centers in diamond
• Quantum cryptography based on Bell’s theorem

Discussions

• The number that matters: T2 goes from 371 ns to 1.27 ms just by adding 4 CPMG refocusing pulses, a 3400x jump. All noise is slow and refocusable. Switch to isotopically pure 12C diamond and the predic [bsky, 0 points, 0 comments]

Related

• Silicon-Vacancy Spin Qubit in Diamond: A Quantum Memory Exceeding 10 ms with Single-Shot State Readout
• All-optical initialization, readout, and coherent preparation of single silicon-vacancy spins in diamond
• Raman Excited Spin Coherences in N-V Diamond
• Microwave-Based Quantum Control and Coherence Protection of Tin-Vacancy Spin Qubits in a Strain-Tuned Diamond-Membrane Heterostructure
• Lifetime-Limited and Tunable Emission from Single Charge-Stabilized Nickel Vacancy Centers in Diamond