Fault-tolerant preparation of the initial state in D"unnweber et al.'s autonomous quantum computer

Establish a fault-tolerant method for preparing the requisite initial state of D"unnweber et al.'s quantum extension of Gács' self-simulating construction using the same fixed interactions that subsequently perform the computation.

Background

The paper compares its locally decodable, two-dimensional architecture with an alternative construction by D"unnweber et al. based on a quantum generalization of Gács' self-simulation techniques. Although that alternative supports scalable fault-tolerant quantum computation without reliable classical computation, its required initial state must itself be prepared fault tolerantly using the same fixed interactions that later implement the computation.

The paper identifies this preparation task as unresolved. Solving it would complete an autonomous, interaction-fixed implementation of the D"unnweber et al. architecture rather than merely establishing fault-tolerant computation conditional on access to the requisite initial state.