Quantum repeater primitive
Entanglement swapping
Intermediate Bell measurements create entanglement between nodes that never directly interacted.
Core idea
Two shorter entangled links are joined by measuring the middle qubits, with fidelity and success tradeoffs.
Minimal mathematics
The MVP route model uses F_swap = F1 F2 + ((1 - F1)(1 - F2))/3 as a Werner-state proxy.
Typical assumptions
- Bell measurements are represented by scalar success/fidelity proxies
- Memory decoherence is simplified
- Classical signaling latency is additive
Common failure modes
- Swap failure
- Fidelity decay
- Memory timeout
Related tools
References
- Zukowski et al., entanglement swapping
- Quantum repeater literature