Future information technologies: 3D Quantum Spin Liquid revealed
Two of the four magnetic interactions form a new three-dimensional network of corner-sharing triangles, known as the hyper-hyperkagome lattice, leading to the quantum spin liquid behavior in PbCuTe2O6. © HZB
Quantum Spin Liquids are candidates for potential use in future information technologies. So far, Quantum Spin Liquids have usually only been found in one or two dimensional magnetic systems only. Now an international team led by HZB scientists has investigated crystals of PbCuTe2O6 with neutron experiments at ISIS, NIST and ILL. They found spin liquid behaviour in 3D, due to a so called hyper hyperkagome lattice. The experimental data fit extremely well to theoretical simulations also done at HZB.
IT devices today are based on electronic processes in semiconductors. The next real breakthrough could be to exploit other quantum phenomena, for example interactions between tiny magnetic moments in the material, the so-called spins. So-called quantum-spin liquid materials could be candidates for such new technologies. They differ significantly from conventional magnetic materials because quantum fluctuations dominate the magnetic interactions: Due to geometric constraints in the crystal lattice, spins cannot all "freeze" together in a ground state - they are forced to fluctuate, even at temperatures close to absolute zero.
Quantum spin liquids: a rare phenomenon
Quantum spin liquids are rare and have so far been found mainly in two-dimensional magnetic systems. Three-dimensional isotropic spin liquids are mostly sought in materials where the magnetic ions form pyrochlore or hyperkagome lattices. An international team led by HZB physicist Prof. Bella Lake has now investigated samples of PbCuTe2O6, which has a three-dimensional lattice called hyper-hyperkagome lattice.
Magnetic interactions simulated
HZB physicist Prof. Johannes Reuther calculated the behaviour of such a three-dimensional hyper-hyperkagome lattice with four magnetic interactions and showed that the system exhibits quantum-spin liquid behaviour with a specific magnetic energy spectrum.
Experiments at neutron sources find 3D quantum spin liquid
With neutron experiments at ISIS, UK, ILL, France and NIST, USA the team was able to prove the very subtle signals of this predicted behaviour. "We were surprised how well our data fit into the calculations. This gives us hope that we can really understand what happens in these systems," explains first author Dr. Shravani Chillal, HZB.
- Catalysis research at HZB gets new facilityAs part of the CatLab project, HZB has acquired a unique facility for measuring the catalytic performance of thin-film catalysts. Built by ILS in Adlershof, it has now been delivered. The facility consists of a total of eight chemical reactors in which catalytic systems can be tested. At over €2.5 million, this is the largest single investment in the CatLab project.
- Protein crystallography at BESSY II: faster, better and more and more automaticMany diseases are linked to malfunctions of proteins in the organism. The three-dimensional architecture of these molecules is often highly complex, but it can provide valuable insights into biological processes and the development of drugs. X-ray diffraction at the MX beamlines of BESSY II can be used to decipher the 3D structure of proteins. To date, more than 5000 structures have been solved at the three MX beamlines. Here, we present a review and an outlook with Manfred Weiss, head of the research group for macromolecular crystallography.
- 5000th protein structure at BESSY II: Starting point for a COVID drugMany proteins have a complex architecture that enables biological functions. Molecules can bind to specific sites on a protein and alter its function. A team at HZB has now investigated the Nsp1 protein, which plays a role in infection with the SARS-CoV-2 virus. They analysed protein crystals, previously mixed with molecules from a fragment library, and discovered a total of 21 candidates as starting points for drug development. At the same time, they also decoded the 5000th structure at BESSY II.