This article is terrible. Just atrocious. How did this get published in Scientific American?

In theory and to some extent in practice its tenets demand that a particle can appear to be in two places at once—a paradoxical phenomenon known as superposition….

That is not what “superposition” means. Not what it means at all. Not even close — either the formal interpretation of the informal (but equally correct) one. A trip to Wikipedia will clear that right up.

Applying the superposition principle to a quantum mechanical particle, the configurations of the particle are all positions, so the superpositions make a complex wave in space. The coefficients of the linear superposition are a wave which describes the particle as best as is possible, and whose amplitude interferes according to the Huygens principle.

That is what superposition means. There’s no two damn particles anywhere.

[A]nd that two particles can become “entangled,” sharing information across arbitrarily large distances through some still-unknown mechanism.

That is also not what “entanglement” means. There is no information-sharing in this sense going on here. There is only mutual information where the quantum state of the system cannot be described without the other particle (or whatever), no matter how far away it might be. So, no, they do not share information across any distances. But they do share a quantum state which experiences a wavefunction collapse on observation of either of the pair of particles. (Which is, you know, cool enough in itself.)

And Schrödinger’s cat again. I shake my head in shame and despair. That cat is the most abused feline in the entire universe, quantum or otherwise.

I could go on. Quantum mechanics is weird enough without being absolutely wrong about the actual facts of it. I mean it’s a 100% scientific truth that local realism is not preserved in this universe. Isn’t that weird enough, rather than writing all that crappy pap and pappy crap?