Quantum Internet: A Capability Roadmap
A quantum internet roadmap should connect demonstrated capabilities to user tasks and expose the next missing interface. The research question is what additional physical and protocol capability makes a new service possible. A distance record or a collection of incompatible component records is not an operational roadmap.
Required background. Quantum network architectures develops nodes, links, trust boundaries and entanglement services.
Capabilities form a partial order
Section titled “Capabilities form a partial order”Prepare-and-measure communication, heralded entanglement, entanglement storage, local quantum processing and fault-tolerant distributed operations enable different tasks. Some applications need only a subset. Wehner, Elkouss and Hanson’s roadmap is useful because it links capability to applications rather than treating every experimental network as the same object. Roadmap.
A useful service request might specify two endpoints, minimum fidelity, deadline and number of pairs. The network returns success, a resource identifier and the known frame, or an explicit failure. These semantics make laboratory components composable and reveal whether classical signaling, memory or photon production dominates.
What the cited evidence does and does not show
Section titled “What the cited evidence does and does not show”Established: a two-node memory experiment connected silicon-vacancy registers through telecom fiber, including deployed infrastructure. That tests remote entanglement and storage in a particular architecture. It does not demonstrate arbitrary routing, multi-user congestion control or interoperable fault-tolerant modules. 2024 experiment.
Active: dependable requests across multiple nodes, shared-resource scheduling, calibration under load and verifiable service guarantees. Conjectural: forecasts of widespread application value before an advantage over classical communication or local processing is quantified.
Choosing between research paths
Section titled “Choosing between research paths”Hardware work can improve a channel’s loss/noise tradeoff. Protocol work can exploit the channel more efficiently without changing it. Application work can relax an unnecessary fidelity or timing constraint. These approaches compete through the same service contract; a protocol that assumes unlimited memories is not a substitute for a realistic hardware improvement.
The important unresolved question is often whether an application’s required state can be delivered before decoherence removes its benefit. Repeater, memory and verification projects should connect to that requirement.
Graduate project: a capability-to-application audit
Section titled “Graduate project: a capability-to-application audit”Select one proposed application and one published network experiment. Build a table mapping every required primitive to measured evidence, a simulated projection or a missing capability. Quantify the end-to-end rate using only mutually compatible parameters. A laptop and primary supplementary information suffice.
The baseline is direct communication or an application without distributed entanglement. Failure tests replace perfect memories with measured decay, charge classical signaling, and include initialization outages. Deliver a dependency diagram and the smallest additional experiment that would close one missing edge. Research begins when that experiment, protocol or bound changes application feasibility; completing a roadmap graphic alone is not enough.
Entry points and update criteria
Section titled “Entry points and update criteria”Read the capability roadmap and one complete experiment. Update the assessment after demonstrated composition of previously separate capabilities or an application-level cost advantage. Source search date: 11 October 2026; selected evidence horizon: 2018–2024, not an exhaustive current deployment report.