14-qubit entanglement: creation and coherence

TL;DR

This paper reports the creation of 14-qubit GHZ states and analyzes their coherence decay, demonstrating a quadratic decay pattern consistent with a Gaussian phase noise model relevant for quantum computing and metrology.

Contribution

It demonstrates the creation of large-scale entangled states with up to 14 qubits and provides a coherence decay model applicable to current quantum systems.

Findings

Created GHZ states with up to 14 qubits

Observed quadratic decay of coherence over time

Model agrees with experimental data for correlated phase noise

Abstract

We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the number of qubits. The observed decay agrees with a theoretical model which assumes a system affected by correlated, Gaussian phase noise. This model holds for the majority of current experimental systems developed towards quantum computation and quantum metrology.