19 January 2017

Symmetry reduction in a quantum kagomé antiferromagnet

The angular dependence of the electron Zeeman splitting with the magnetic field in the plane perpendicular to the crystal c-axis. The angular dependence of the electron Zeeman splitting with the magnetic field in the plane perpendicular to the crystal c-axis.

This area of research could help scientists understand high-temperature superconductivity and other mysteries.

What did scientists discover?

In one of the rare examples of a material with a quantum spin liquid ground state, magnetic signals associated with impurities indicate an unexpected breaking of the triangular symmetry of the material at low temperatures.

Why is this important?

Finding ideal examples of the two-dimensional quantum kagomé antiferromagnet is of immense interest and importance in the condensed matter physics community because they represent a paradigm for correlated disordered spin states and a host for the long-sought-after quantum spin liquid. Studies of such systems are expected to have far-reaching consequences for understanding a wide class of problems, including high-temperature superconductivity. The quantum spin liquid ground state predicted for the ideal kagomé lattice is believed to be highly unstable. Therefore, it is interesting to explore any instabilities that might result from disorder and its symmetry-breaking influences.

Who did the research?

A. Zorko1, M.Herak2, M. Gomilšek1, J. van Tol3, M. Velásquez4, P. Khuntia5, F. Bert5, and P. Mendels5

1Jožef Stefan Institute Slovenia; 2Institute of Physics, Croatia; 3National High Magnetic Field Laboratory, Florida State University; 4CNRS Bordeaux, France; 5CNRS Paris-Saclay, France

Why did they need the MagLab?

These ESR experiments require high resolving power to measure the g-anisotropy, which calls for high frequencies and magnetic fields, since resolution scales linearly with frequency and field. They also require sample rotation available at the MagLab (and not available from commercial instrumentation) to resolve the many components of the spectra (see sinusoidal oscillations in the image above).

THE TOOLS THEY USED

This research was conducted in the Heterodyne Quasi-Optical Spectrometer in the MagLab's EMR Facility.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490); Zorko (SRA* BI-HR/14-15-003, BI-FR/15-16-PROTEUS-004, P1-0125); Gomilšek (CSF§ UIP-2014-09-9775); Mendels (ANR†-12-BS04-0021)


For more information, contact Hans van Tol .

Details

  • Research Area: Magnetism and Magnetic Materials, Quantum Fluids and Solids, Topological Matter
  • Research Initiatives: Materials
  • Facility / Program: EMR
  • Year: 2017
Last modified on 20 January 2017