Is Fault Welcoming Quantum Computing Realistic?

An error-corrected, fault tolerant quantum computer is one of the most important long term goals of quantum computing research. In these systems random noise is an obstacle that must be overcome through error correction. Here we explore a new possibility, fault-welcoming quantum computing, where a system can not only maintain a quantum speedup for a given (likely non-universal) class of quantum algorithms against realistic noise, but actually performs better than an idealized copy with no noise. We modify flux qubit quantum annealing by including random, coherent low-frequency oscillations in the directions of the transverse field terms during evolution. Through analytical and numerical calculations, we show that this produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and thus should be widely applicable to other hard spin glass problems. Further, we show that this speedup should be resilient to two realistic noise channels, and that another channel, bath-assisted phase transitions, accelerates optimization and may outweigh the others, thus potentially making the system fault welcoming. The modifications we consider could be explored with current technology.