top of page

A New State of Matter Was Discovered Through a Physics Experiment: Breaking Time-Reversal Symmetry

By: April Carson

The basic tenet of superconductivity is that electrons pair together. Could they, on the other hand, condense into foursomes? Recent discoveries have indicated that this is possible, and a physicist at KTH Royal Institute of Technology presented experimental proof of this quadrupling effect and the mechanism by which it occurs for the first time today.

According to reports in Nature Physics, Egor Babaev and coworkers revealed evidence for fermion quadrupling in a series of experimental investigations on the iron-based material Ba1-xKxFe2As2. The findings come almost 20 years after Babaev first predicted it, and eight years after he published a paper suggesting that it might be observed in experiments on Ba1-xKxFe2As2, a so-called '122' iron pnictide.

Superconductors -

In superconductivity, two or more electrons become "entangled," which means they are bound together in such a way that their energies are perfectly balanced. This occurs in materials as a result of the pairing of electrons rather than repelling one another, as they would in a vacuum. The phenomenon was first characterized by Leon Cooper, John Bardeen, and Robert Schrieffer in 1957, for which they earned the Nobel Prize.

Electrons are fermions, or particles with half-integer spin. Because there can be only one state of lowest energy, two electrons cannot occupy the same quantum state simultaneously. Yet when the researchers measured pairs of entangled electrons inside Ba1-xKxFe2As2, they found that the electrons appeared to be in two separate quantum states at the same time.

Cooper-pairs are two electrons that are “opposites that attract.” Normally, two negatively charged subatomic particles would repel each other strongly. However, at low temperatures in a crystal, they become loosely linked in pairs, resulting in a significant long-range order. The current of electrons no longer scatters from flaws or obstructions, and a conductor loses all electrical resistance and converts to a new state of matter: a superconductor.

The theoretical concept of four-fermion condensates has only recently been accepted.

For a fermion quadrupling state to occur, there must be something that prevents pair condensation and their flow without resistance while allowing four-electron composite condensation, according to Babaev.

When the Bardeen-Cooper-Schrieffer hypothesis didn't allow for such behavior, it sparked a scientific debate when Babaev's experimental collaborator at Technische Universität Dresden, Vadim Grinenko, discovered in 2018 the first indications of a fermion quadrupling condensate.

After three years of research and testing in several labs around the world, this discovery was validated.

Time-Reversal Symmetry -

According to Babaev, one of the discoveries made is that fermionic quadruple condensates spontaneously break time-reversal symmetry. In physics, time-reversal symmetry refers to a mathematical operation of replacing the expression for time with its negative in equations or formulas so that they describe an event in which time runs backward or all particles are reversed in their motion.

The fundamental rules of physics remain intact if one inverts the passage of time. That also applies to normal superconductors: regardless of whether the arrow of time is reversed, a typical superconductor would continue to be in its superconducting state.

“However, in the case of a four-fermion condensate that we describe, the time reversal places it in a different condition,” he adds.

“It will probably take many years of research to fully understand this state,” he says. “The experiments open up a number of new questions, revealing a number of other unusual properties associated with its reaction to thermal gradients, magnetic fields and ultrasound that still have to be better understood.”

Do you want to be a part owner of a successful firm that is already profitable and is rapidly expanding in a huge market with few competitors? Then join the movement by investing in 4BiddenKnowledge TV! Watch this quick video to learn more!



About the Blogger:

April Carson is the daughter of Billy Carson. She received her bachelor's degree in Social Sciences from Jacksonville University, where she was also on the Women's Basketball team. She now has a successful clothing company that specializes in organic baby clothes and other items. Take a look at their most popular fall fashions on

To read more of April's blogs, check out her website! She publishes new blogs on a daily basis, including the most helpful mommy advice and baby care tips! Follow on IG @bossbabymav





bottom of page