Speaker
Description
Distributed quantum computation is currently constrained by the latency of probabilistic inter-module entanglement. Traditional architectures rely on sequential teleportation, where the total runtime scales with the sum of geometric waiting times for each successful Bell-pair generation. In this work, we propose "stitched measurement-based quantum computation" (stitched MBQC) as a deterministic alternative that parallelizes these probabilistic events.
Rather than establishing links gate-by-gate, our protocol prepares local photonic graph states within each module and "stitches" them at the boundaries using parallel photonic Bell-state measurements (BSMs). We derive the stabilizer formalism showing that a successful BSM on emitted photons projects the boundary qubits into a joint stabilizer state, effectively adding a graph edge between modules without requiring round-trip signaling. Once a sufficient number of edges are established, the modules form a single distributed cluster state, allowing a full layer of cross-module gates to be executed deterministically via single-qubit measurements.
This approach transforms the latency scaling from a sum of geometric random variables to a single negative-binomial distribution, significantly thinning the heavy tail associated with entanglement attempts. Using custom MBQC gadgets designed for Grover’s search and QAOA, we demonstrate through simulation that stitching reduces expected latency by a factor of 3–6$\times$ compared to standard teleportation.
| Keyword-1 | Distributed Quantum Computing |
|---|---|
| Keyword-2 | MBQC |
| Keyword-3 | Photonic Graph States |