Excitonium: Scientists discover new form of matter

Researchers at the University of Illinois have announced discovery of new form of matter called excitonium. The existence of this strange and mysterious type of matter was theorized after the term excitonium was theoretically coined by Harvard theoretical physicist named Bert Halper in the 1960s,

Key Facts

To prove existence of excitons, scientists had studied crystals doped with dichalcogenide titanium diselenide (1T-TiSe2), a transition metal. This material is made up of a kind of boson, a composite particle that could allow matter to act as a superfluid, superconductor, or even as an insulating electronic crystal. Scientists were able to observe existence of excitonium using novel technique called momentum-resolved electron energy-loss spectroscopy (M-EELS).


Excitonium is a condensate made up of excitons and exhibits macroscopic quantum phenomena just like a superconductor. Excitons are particles that are formed in a very strange quantum mechanical pairing. They are obtained by combining escaped electrons and “holes”.
This quirky quantum-mechanical pairing is possible because, in semiconductors, electrons on edge of one energy level in atom are able to jump into the next energy level when excited, leaving behind a “hole” in previous level. This hole acts like a positively charged particle, attracting the negatively charged electron that escaped.


Excitonium exhibits macroscopic quantum phenomena, like a superconductor and this findings holds great promise for unlocking further quantum mechanical mysteries. As a superconductor and superfluid, this material can be used to further existing technologies. These applications, especially those in practical technologies, are purely speculative at this point.