  We have studied carefully the behaviors of entangled qubits on the IBM
Rochester with various connectivities and under a "noisy" environment. A phase
trajectory analysis based on our measurements of the GHZ-like states is
performed. Our results point to an important fact that entangled qubits are
"protected" against environmental noise by a scaling property that impacts only
the weighting of their amplitudes. The reproducibility of most measurements has
been confirmed within a reasonably short gate operation time. But there still
are a few combinations of qubits that show significant entanglement evolution
in the form of transitions between quantum states. The phase trajectory of an
entangled evolution, and the impact of the sudden death of GHZ-like states and
the revival of newly excited states are analyzed in details. All observed
trajectories of entangled qubits arise under the influences of the newly
excited states in a "noisy" intermediate-scale quantum (NISQ) computer.

Quantum Physics