Quantum decoherence and its mitigation

Abstract

One of the greatest challenges in quantum information science is the development of methods for efficiently maintaining the uniquely quantum properties of states during the performance of quantum information-processing tasks. In particular, quantum information-processing hardware designs are faced with two competing requirements, that of strong interactions between their internal components for the performance of controlled quantum gates and that of isolating qubits from the environment in which the hardware operates.¹ Quantum decoherence is the loss of coherence within a quantum state behind the second of these requirements, and can take the form of dephasing or the loss of state population described by a nonunitary evolution of local system states, due to unwanted interaction with the environment.² This interaction generally necessitates the correction of errors it induces, which are highly detrimental to quantum information-processing tasks.

See, for example, [429].

A more general theory of decoherence was laid out by Roland Omnès in [317].