No.

For one, the PRL paper linked here is highly speculative, using a phenomenological model and a lot of assumption and extrapolation. It's full of "may" and "if" and "possibility".

Furthermore, what they suggest appears like it would only work as an (inefficient) energy storage; it's not a primary energy source, since you'd have to spend lots of energy first to create this very hypothetical quark matter,and then regain some of that energy as you feed the quark matter with slow neutrons.

Finally, assuming everything above actually works, this would be a slow energy release, not fast like in a nuke.

The inefficiency is comparable to those who advocate using antimatter as the ultimate fuel, somehow forgetting that it needs to be manufactured somehow at great energetic expense. If one has a Dyson sphere’s worth of energy to power one’s antimatter-production plant for one’s ultrarelitivistic fleet, that’s great; but if you’re thinking of massive conventional fusion reactors as an intermediary might as well just take those (and their large amounts of light fuels) along for the ride and cut out the intermediary product.

What would be the point ? We can already destroy a medium country with a few nukes. We probably have enough nukes to blow the entire planet.

What would a bigger boom accomplish ?

Not from the sounds of it.

It's pretty hard to beat existing nuclear weapons, honestly, and even if you could, existing nuclear weapons will be much cheaper for a long time. The bulk of them is already delivery mechanism rather than the warhead.

Who needs deadlier stuff than nukes? Let's root for Quark matter drives instead.