No Tile Left Behind: Multiprogramming for Surface-Code Architectures

2026-04-28

AI Summary

Fault-tolerant quantum multiprogramming faces significant challenges under surface code architectures due to structural constraints imposed by data qubits, ancilla qubits, and magic state resources, as well as layout compactness and contention for shared infrastructure—limitations that render conventional NISQ-era approaches inapplicable. This work presents the first systematic modeling of these structured resource constraints and introduces a formal framework for surface-code-aware fault-tolerant multiprogramming. The proposed approach incorporates static resource allocation, a hierarchy-aware online scheduling mechanism, and integrated dynamic magic state generation. Experimental evaluation on Clifford+T synthesis workloads demonstrates a normalized speedup of 3.1×, representing a 29% improvement over current baselines while maintaining a low average slowdown ratio.

Abstract

Fault-tolerant quantum computing (FTQC) is emerging as the architectural regime in which practical large-scale quantum workloads will execute. In this setting, however, multiprogramming is no longer a matter of partitioning a flat pool of qubits. Quantum error correction exposes a structured floorplan of data tiles, ancilla tiles, and magic-state service resources, so concurrent execution must account for compact placement, connectivity, routing headroom, and shared support infrastructure. This makes FTQC multiprogramming fundamentally harder than its NISQ counterpart: admission decisions can fragment the remaining floorplan, conservative reservations can waste ancilla, and dynamic contention across data, ancilla, and magic-state resources can degrade both throughput and quality of service. In this work, we develop a formal framework for FTQC multiprogramming that captures these structural constraints and their runtime implications. We formulate the baseline static allocation problem, extend it to limited-resource and online settings through hierarchy-aware scheduling policies, and further generalize it to cultivation-enabled architectures with dynamic magic-state generation. Through simulation on synthetic Clifford+T workloads, the proposed scheduler achieves a normalized system speedup of 3.1x, improving over prior FTQC multiprogramming baselines by ~29% while maintaining low mean slowdown.

Problem

• fault-tolerant quantum computing
• multiprogramming
• surface code
• resource allocation
• magic-state distillation

Innovation

• fault-tolerant quantum computing
• surface code
• multiprogramming
• magic-state distillation
• hierarchical scheduling