Effects of low-frequency noise cross-correlations in coupled superconducting qubits

Abstract

We study the effects of correlated low-frequency noise sources acting on a two-qubit gate in a fixed coupling scheme. A decoherence model for the spatial and cross-talk correlations is introduced. The efficiency inside the SWAP subspace is analyzed by combining analytic results based on the adiabatic approximation and numerical simulations. Results critically depend on amplitude of the low-frequency noise with respect to the qubits' coupling strength. Correlations between noise sources induce different qualitative behavior depending on the values of the above parameters. The possibility to reduce dephasing due to correlated low-frequency noise by a recalibration protocol is discussed. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.