  We report the experimental nondemolition measurement of coherence,
predictability and concurrence on a system of two qubits. The quantum circuits
proposed by De Melo et al. are implemented on IBM Q (superconducting circuit)
and IonQ (trapped ion) quantum computers. Three criteria are used to compare
the performance of the different machines on this task: measurement accuracy,
nondemolition of the observable, and quantum state preparation. We find that
the IonQ quantum computer provides constant state fidelity through the
nondemolition process, outperforming IBM Q systems on which the fidelity
consequently drops after the measurement. Our study compares the current
performance of these two technologies at different stages of the nondemolition
measurement of bipartite complementarity.
