Lazy Quantum Walks with Native Multiqubit Gates: Quantum walks (QWs) as a benchmark for effective multiqubit gate fidelities; via detailed realistic error modelling for neutral atom hardware we pinpoint the native multiqubit gate sweet spot for standard & lazy discrete QWs. arxiv.org/abs/2511.21608
!["Figure 6: Final fidelity of the final position states between errorless and simulated error 1q-coin (circles) and 2q-coin (triangles) QWs on 2n-node rings, using native gate set G(max(r) = 3). Pink solid lines denote QWs on 4-node rings, dashed blue on 8-node rings, and dotted gold lines on 16-node rings. IBM results (using native gates of max(r) = 2) [15] for 1q-coin QWs are also shown for comparison in crosses." Figure shows that 1q-coin QW on 4-node ring has final state fidelity >0.9 for 21 steps; 2q-coin (lazy) QW on 4-node and 1q-coin QW on 8-node has fidelity >0.9 for 10 steps and >0.8 for 20 steps; 2q-coin QW on 8-node and 1q-coin QW on 16-node has >0.9 for 5 steps, >0.8 for 8 steps, and >0.5 for 21 steps; lastly 2q-coin QW on 16-node >0.9 for 2 steps, >0.8 for 4 steps, and >0.5 for 10 steps. In all cases this is a marked improved over IBM results.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:i3p2yl6mljsrlcit555ctvyz/bafkreifqrhhip34q556octjejenh2p4pwzfy2jzhrlbddtulusauzc6bhq)
