Alternate example for plot_bloch_multivector

Environment

• Qiskit Terra version: 0.19.1

What is happening?

The example for the plot_bloch_multivector doc looks broken - https://qiskit.org/documentation/stubs/qiskit.visualization.plot_bloch_multivector.html#qiskit.visualization.plot_bloch_multivector

The example is trying to visualize a bell state and the entanglement isn’t clearly visualizable with bloch sphere and hence there are 2 blank bloch spheres that may not depict the idea of the function clearly!

How can we reproduce the issue?

The issue can be checked out here! https://qiskit.org/documentation/stubs/qiskit.visualization.plot_bloch_multivector.html#qiskit.visualization.plot_bloch_multivector

LIne in docs - https://github.com/Qiskit/qiskit-terra/blob/4301fc47c73507e489dbafc7bae490ab29736daa/qiskit/visualization/state_visualization.py#L263-L277

What should happen?

An example that clearly depicts a use case for the plot_bloch_multivector for people checking out the documentation

Any suggestions?

Since the examples are uniform across all the sections of https://qiskit.org/documentation/apidoc/visualization.html#counts-and-state-visualizations, contributor may have to take into consideration that if at all this example is to be modified, the subsection docs plot_histogram , plot_state_city, plot_state_hinton, plot_state_paulivec and plot_state_qsphere may have to be similarly accommodated since currently all seem to be using the same example across to depict the visualisation ideas uniformly in their respective sections.

[MaxMinerva123]

Oh I see. I’m really new to Qiskit and Quantum Computing in general but yeah I didn’t know swapping the operands of cx doesn’t create an entangled state Thanks!

[jakelishman]

Sure, I’ll assign this one to you so people know you’re working on it.