  In this paper we study reusable magic states. These states are a special
subset of the standard magic states. Once distilled, reusable magic states can
be used, repeatedly, to apply some unitary U. Given this property, reusable
magic states have the potential to greatly lower qubit and gate overheads in
fault-tolerant quantum computation. While these states are promising, we
provide a strong argument for their limited computational power. Specifically,
we show that if reusable magic states can be used to apply non-Clifford
unitaries, then we can exploit them to efficiently simulate poly-sized quantum
circuits on a classical computer.
