First a definition for this question, because there are many kinds of sci-fi out there and they sometimes liberally use cool sounding words without explaining them:
A disruptor is a kind of weapon that weakens, or “disrupts”, either material bonds (breaking a material into molecules), molecular bonds (breaking a molecule into atoms), or atomic bonds (breaking an atomic nucleus into protons, netrons, and free electrons. Almost like instantly turning into plasma).
Temperature can do these things, but the idea behind a disruptor, specifically, is that it happens through some kind of catalyst, rather than brute-forcing with insane amounts of heat.
Would such a weapon physically be possible (even if we don’t know how to make them just yet)?
How would a target realistically behave when hit by a disruptor?
Unfortunately, this is one of those fun ideas that simply won’t ever be possible. Even if we start with the easy one of just breaking chemical bonds, those bonds exist because it reduces the total energy of the system.
To “disrupt” those bonds, energy must be supplied, and to do it for even a small amount of material would require a tremendous amount of energy. Delivering that much energy over a distance just isn’t possible because atmosphere in between would also be “disrupted”. The disrupted material would also fly apart at high speeds and high temperatures. So any type of “ray” or “gun” would just turn into a bomb with a pistol grip trigger. I expect that the user experience testing would have lots of very negative reviews.