Spin-Photon MOC

Curated map of Zoo entries in the Spin-Photon family.

Entries

Entry	Type	Status
nv-center-qubit	qubit	demonstrated
rare-earth-ion-qubit	qubit	demonstrated
silicon-carbide-defect-qubit	qubit	demonstrated
siv-color-center-qubit	qubit	demonstrated
t-center-qubit	qubit	demonstrated

Composition

• qubit: 5

Conceptual anchors

• divincenzo-criteria criteria 6 and 7 organize this family more cleanly than gate-centric comparisons, because every note here is really about turning a local spin memory into a networkable module.
• coherence-time-hierarchy captures the main engineering cost of those cleaner optical interfaces: spectral quality, cryogenic burden, and memory lifetime move together rather than independently.
• quantum-transduction is a useful boundary note: platforms here are most interesting when they reduce or avoid transduction pain by emitting photons that are already spectrally useful for networking.

Curated synthesis

This family is best read as the network-emitter-optimized descendant branch of the broader defect-spin story.

1. siv-color-center-qubit is the optical-quality-first branch

   • Group-IV vacancy centers buy much cleaner photons than NV by using inversion symmetry to suppress electric-field sensitivity.
   • The price is cryogenic severity: SiV offers excellent optical coherence but drags in a harsher phonon-temperature constraint, while SnV eases that constraint at the cost of a less mature platform.

2. t-center-qubit is the telecom-and-integration-first branch

   • The central claim is not just “another defect spin,” but “a spin-photon node already living in silicon and already emitting in the telecom O-band.”
   • Route here when silicon-photonics compatibility, fibre-network realism, or modular distributed-computing fit matters more than diamond-emitter maturity.

3. The family-level comparison is about which systems burden you want to pay

   • SiV/SnV pay heavily in temperature to buy cleaner optical lines and nanophotonic performance.
   • T centers pay in platform maturity and benchmark depth, but may save substantial systems complexity by starting inside silicon and near telecom wavelengths.
   • silicon-carbide-defect-qubit trades some emitter uniformity for wafer-scale wide-bandgap processing and a broad defect palette.
   • rare-earth-ion-qubit is the long-memory and spectral-multiplexing branch: Er supplies native C-band photons, while Yb nanophotonic nodes have demonstrated multiplexed remote entanglement.

4. This MOC should usually be read against color-center-moc, not in isolation

   • The useful contrast is not “which color center is best?” but “when does a defect stop being primarily a local-spin story and become primarily a network-emitter story?”
   • nv-center-qubit remains the better anchor for room-temperature local-memory maturity, while this page owns the branch where optical interface quality is the main selection criterion.

Networking-burden comparison

If the architecture pain point is…	Best first stop	Why
Photon indistinguishability and cavity-integrated nanophotonics	siv-color-center-qubit	Inversion symmetry and high ZPL fraction are the whole point.
Native telecom compatibility and silicon photonics	t-center-qubit	It starts much closer to the fibre stack the network already wants.
Mature room-temperature defect-spin control with a real local register	color-center-moc	That is still the NV-centered branch, not this one.
Avoiding a large microwave-to-optical conversion stack	t-center-qubit, then quantum-transduction	Native O-band emission can remove part of the transduction burden rather than merely optimizing around it.
Choosing between clean photons and a gentler cryogenic envelope	Read both entries	SiV buys the best optics; SnV and T centers relax the systems burden in different ways.

Network-emitter routing table

If the real question is…	Start here?	Why
Which defect-spin platform gives the cleanest photons for remote entanglement?	Yes	That is the defining purpose of this family.
Which branch wins on nanophotonic optical quality even if the fridge burden is harsher?	Yes	siv-color-center-qubit is the clean-photon-first reference case.
Which branch best reduces downstream telecom integration pain?	Yes	t-center-qubit is the silicon-and-telecom-first route.
Which defect-spin qubit is the most mature room-temperature local memory platform?	No	Hand back to color-center-moc and nv-center-qubit.
Is native emission already close enough to the network target to avoid a major transduction stack?	Yes	Read this MOC, then cross-check with quantum-transduction.

Routing rule

• Read this MOC when the primary question is how to build a better spin-to-photon interface, not how to get the most mature defect-spin qubit overall.
• Hand back to color-center-moc when room-temperature operation, ODMR-style control, or local defect-spin memory maturity becomes the main criterion.
• Use quantum-transduction as the downstream systems check: if a platform already emits where the network wants to live, that is a real architectural advantage, not just a spectroscopy detail.
• Treat siv-color-center-qubit and t-center-qubit as complementary answers to different network bottlenecks, not as a simple maturity ladder.