Decoherence of up to 8-qubit entangled states in a 16-qubit superconducting quantum processor
Asier Ozaeta, Peter L McMahon · Quantum Science and Technology · 2019
Abstract We report on the coherence of Greenberger–Horne–Zeilinger (GHZ) states comprised of up to 8 qubits in the IBM ibmqx5 16-qubit quantum processor. In particular, we evaluate the coherence of GHZ states with N = 1, …, 8 qubits 4 , as a function of a delay time between state creation and measurement. We find that the decay in coherence occurs at a rate that is linear in the number of qubits. This is consistent with a model in which the dominant noise affecting the system is uncorrelated across qubits.