Publish Date: 17.08.2017

Category: News from the University

The group of researchers from the Institute Jozef Stefan, Faculty of mathematics and physics and Faculty of civil and geodetic engineering of University of Ljubljana, Martin Klanjšek, Andrej Zorko, Rok Žitko, Jernej Mravlje, Zvonko Jagličić, Peter Prelovšek, Dragan Mihailovič and Denis Arčon in a publication published in the prestigious journal Nature Physics reported on the discovery of quantum spin liquid in layered crystal TaS2 with which they solved the mystery of magnetism of this important model system that confused researchers for over 40 years.

Magnetic moments are at sufficiently high temperature completely disordered (they form the so-called paramagnet), which we can roughly compare with the gas aggregate state. If the magnetic systems is cooled, then magnetic moments eventually order – for instance into antiferromagnetic order – similarly as atoms order in crystals. On the other hand, magnetic states, which would be analogous to liquids, have been theoretically predicted, but very rarely observed in the nature. 

Spin liquid was first predicted by P.W. Anderson more than 40 years ago, when he researched the unusual magnetic properties of layered TaS2. The group of Slovenian physicists from Institute Jožef Stefan and University of Ljubljana discovered, that the electronic magnetic moments localised on Ta stars, do not magnetically order even at -273.08 oC and that they indeed form the new state of quantum spin liquid. What is interesting with this state is that it shows long-distance entanglement – in other words, it is a macroscopic quantum state, similar, as it is superconductivity. This discovery opens completely new opportunities for the understanding of this enigmatic magnetic state and for the development of novel quantum technologies. 

Link to the article.Publication of Slovenian physicists in the journal Nature Physics