Context:

• 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,
• 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).

About Excitonium:

• 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.

Source: Indian Express & Wiki