A new state of matter has been spotted in a two-dimensional material called alpha-ruthenium that bears resemblance to graphene. It has been named “quantum spin liquid” state, and is said to come together with strange fermions. The findings are published in Nature Materials.
The quantum spin liquid had been predicted by scientists decades ago; it was thought that it existed in certain types of magnetic materials. However, no evidence had ever been found. Until now. We might need to update our physics and chemistry books.
“This is a new quantum state of matter, which has been predicted but hasn’t been seen before,” says one of the authors, Johannes Knolle, from the University of Cambridge.
This new state of matter can break down electrons into smaller quasiparticles, say the researchers who made the discovery. Note that this does not happen literally: the electrons are not actually broken down into new particles; no new particle has been discovered, which is why the resulting object is called a “quasiparticle”. Rather, quasiparticles constitute a concept that allows physicists to quantify and describe the weird behaviour of particles; in short, the new state of matter is causing electrons to behave in a strange fashion.
Its presence was found through the observation of electron fractionalisation. This process entails electrons ‘splitting apart’ in a quantum spin state, thereby resulting in Majorana fermions. The latter might soon become famous as they are thought to have the potential of becoming the building blocks of quantum computers. Electrons will normally align themselves such that all the north poles are facing the same direction when in a typical magnetic setting which is cooled. However, in the quantum spin liquid state, cooling of the magnetic material to absolute zero will still not cause the usual alignment of the electrons; instead, the electrons will become an entangled mass because of the quantum fluctuations.
The new findings promise to provide a greater understanding of quantum matter. The authors are excited over the discovery as it will likely open new possibilities for more experiments; for instance, the concept of quantum computers seems to be a wee bit closer, given the implications of the fermions.