Slovenian researchers solve 40-year-old quantum physics puzzle

Ljubljana, 10 August - Slovenian researchers have confirmed the existence of a high-temperature quantum spin liquid in TaS2 layered crystal. The discovery, which opens new possibilities in the development of quantum technologies, was published in the Nature Physics magazine at the end of July.

Researchers of the Jožef Stefan Institute, the Ljubljana Faculty of Mathematics and Physics and the University of Ljubljana, led by Denis Arčon, have solved a 40-year-old puzzle.

Philip Warren Anderson, a US Nobel laureate in physics, pointed to the possibility of the phenomenon in theory in 1973, but its experimental realisation turned out to be very elusive, the researchers said in the article.

The researchers found out that magnetic states in the crystal, which are usually completely unordered, similar to the state of gas, can become ordered in a way that can be compared to the liquid state - the quantum spin liquid.

This phenomenon can occur at significantly higher temperatures than the absolute zero, which is a reference temperature in such phenomena.

Arčon explained that the quantum spin liquid had never before persisted in temperatures of up to -93C. This means that the "quantum state is obtainable at temperatures which can quite easily be reached in a laboratory".

"In addition, the possibility to reach this state at such temperatures is important for potential use, as maintaining the state will be significantly less arduous," he added.

According to Arčon, the spin liquid sets forth a completely new state of matter, which means that possibilities of its application can only be guessed at. One of the most frequently mentioned possibilities is the use of spin liquid in quantum computers.