Abstract

Mark Howard (NUI Maynooth)


Universal Quantum Computation using Protected Operations and Distillation

The stabilizer formalism is a mathematical technique, for describing quantum states and quantum processes, which gives special prominence to a subset of all quantum states (stabilizer states) and a subset of all operations (stabilizer operations). A crucial result in quantum information theory says that, whilst stabilizer states and operations are extremely important (they underpin most error-correcting codes, for example), a quantum computer using only this restricted set of states and operations can never be more powerful than a classical computer. The immediate implication is that any useful quantum computer must make use of non-stabilizer states or non-stabilizer operations (i.e., this non- stabilizer resource ``unlocks'' the power of the quantum computer).

Motivated by some proposals for fault-tolerant quantum computing, wherein stabilizer operations are effectively perfect, we analyze the utility of an additional non-stabilizer resource -- in particular when this non-stabilizer resource is highly imperfect.