title: Robust two-qubit quantum registers.
abstract: We carry out a systematic analysis of a pair of coupled qubits, each of which is subject to its own dissipative environment, and argue that a combination of the interqubit couplings which provides for the lowest possible decoherence rates corresponds to the incidence of a double spectral degeneracy in the two-qubit system. We support this general argument by the results of an evolutionary genetic algorithm which can also be used for optimizing time-dependent processes (gates) and their sequences that implement various quantum computing protocols.
authors.affiliation: Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: I A
authors.initials: IA
authors.lastname: Grigorenko
authors.forename: D V
authors.initials: DV
authors.lastname: Khveshchenko