A team of experimentalists at the Max Planck Institute of Quantum Optics (MPQ) and theorists at the Chinese Academy of Sciences (CAS) has succeeded for the first time in populating and stabilizing a new type of molecule, so-called field-linked tetratomic molecules. These "supermolecules" are so fragile that they can only exist at ultracold temperatures. Their existence had long been suspected but has never been demonstrated experimentally—until now.
So, from what I can gather from the word soup here, what this is is basically molecules made of smaller polar molecules like water. They were theorized to exist for a while but we’ve now been able to make them for the first time.
As for what the significance is, well… in the immortal words of Dr. Daniel Jackson from Stargate SG-1… “It’s fascinating”.