First Evidence Of Quantum Spin Liquid, A New State Of Matter Found

A new state of matter predicted 40 years ago has been discovered by an international team of experts. This is the quantum spin liquid, which leads to electrons breaking up, and can help scientists to inch towards creating a quantum computer.

Quantum spin liquids have long been hypothesised as hiding in certain magnetic materials. But they have not actually been seen in nature until now. But currently, electron splitting, their most unique properties, gets a breakthrough.

The team assessed the first signatures of these unique fractional particles called Majorana fermions in a two-dimensional material showing a similar structure to graphene. The results seemed to be similar to the main theoretical model for a quantum spin liquid, the Kitaev model.

These Majorana fermions can be harnessed to create quantum computers going on to make calculations that are not undertaken in standard computers.

"This is a new quantum state of matter, which has been predicted but hasn't been seen before," said Johannes Knolle, co-author of the study and a member of Cambridge University's Cavendish Laboratory.

Usually, it has been observed that in standard magnetic materials, electrons like bar magnets, order themselves at low temperatures. For example, sometimes all the north magnetic poles get aligned in the same direction.

On the other hand, materials with spin liquid states do not align even at the lowest temperatures but form a web caused by quantum fluctuations.

"Until recently, we didn't even know what the experimental fingerprints of a quantum spin liquid would look like," said Dmitry Kovrizhin, co-author of the paper and also from the Cavendish Laboratory. "One thing we've done in previous work is to ask if I were performing experiments on a possible quantum spin liquid, what would I observe?"

"This is a new addition to a short list of known quantum states of matter," Knolle said. "It's an important step for our understanding of quantum matter," Kovrizhin added. "It's fun to have another new quantum state that we've never seen before - it presents us with new possibilities to try new things."

The findings were published in the April 4 issue of Nature Materials.