A remote method of cooling large volumes of matter - without heat transfer to a cold surface - would be revolutionary. As a technology breakthrough, it would be at least as big as the laser or transistor. It would transform society in ways that would lie far outside the function of basic refrigeration. It would revolutionize energy production and conversion, making new and strange types of engines and energy storage methods possible.
It would have huge implications for medical care, materials science, physics, chemistry, and biology.
For these reasons, I expect that it’s impossible, or at least won’t be possible for maybe 100 years. I think it may be impossible on thermodynamic grounds, but I must confess I can’t give a good chain of induction to support this.
Such a device would be a sort of molecular “anti-sound,” similar at a molecular (phonon) level to the anti-sound technology that is used in noise canceling headphones.
It would require at the - very least - immense computing bandwidth, in conjunction with physical sensors of enormous sensitivity and bandwidth.
A microwave works by exciting the molecules in the target item.
I suppose it would be conceivable to “unexcite” them,
but I’m thinking it’s the equivalent of pushing a rope.