AI summaryⓘ
The authors explore how to use a type of quantum error-correcting codes called QLDPC codes on a special spin qubit setup where qubits can be moved (shuttled) around. They improved the way error detection works by accounting for noise caused by this movement, making it possible to connect qubits over longer distances. Using ideas from robotics, they created a scheduling method that moves qubits more efficiently than previous manual attempts. Their simulations show that some QLDPC codes could perform much better than traditional surface codes, offering better error resistance and more efficient encoding. This suggests that their spin qubit system could be a strong candidate for building large quantum computers.
Semiconductor spin qubitsQuantum low-density parity check (QLDPC) codesQuantum error correctionShuttling-based architectureSyndrome extractionSurface codesLogical error ratesFault-tolerant quantum computationQuantum circuit simulationShuttle scheduling algorithm
Authors
Jason D. Chadwick, Frederic T. Chong
Abstract
Semiconductor spin qubits are a promising platform for large-scale quantum computing, but have yet to take full advantage of the broad class of quantum low-density parity check (QLDPC) codes, which promise high encoding rates and efficient logic but require nonlocal connectivity between physical qubits. In this work, we investigate the implementation of QLDPC codes on a tileable, shuttling-based spin qubit architecture. By tailoring syndrome extraction circuits to the shuttling noise model, we significantly improve on previous surface code proposals and extend the feasible shuttling range of the architecture by 5-10x, enabling the implementation of more complex codes with long-range interactions. Taking inspiration from the field of robotics, we develop a coordinated shuttle scheduling algorithm that supports arbitrary codes and use it to benchmark the logical performance of a variety of promising code families. We find that the optimized schedules are up to 86% faster than hand-optimized schedules for certain code families. Through detailed circuit-level simulations, we identify specific QLDPC codes that improve upon prior surface code implementations by orders of magnitude, increasing encoding efficiency and reducing logical error rates. This work demonstrates the potential of shuttling-based spin qubit hardware platforms for scalable and efficient fault-tolerant quantum computation.