Robust two-qubit quantum registers

TL;DR

This paper analyzes coupled qubits under dissipation, identifying optimal inter-qubit couplings that minimize decoherence through spectral degeneracy, supported by genetic algorithm optimization for quantum gate processes.

Contribution

It introduces a systematic approach to optimize two-qubit systems for minimal decoherence using spectral degeneracy and genetic algorithms.

Findings

Double spectral degeneracy reduces decoherence rates.

Genetic algorithms effectively optimize quantum gate sequences.

Optimal coupling configurations enhance qubit coherence.

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 inter-qubit 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 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.