skip to main content NIST Center for Neutron Research NIST Center for Neutron Research National Institute of Standards and Technology
Home Live Data Instruments CHRNS Proposals

Magnetic Excitations in a new Frustrated Magnet

Bella Lake (Helmholtz Zentrum Berlin, Technical University Berlin)

Quantum magnetism is the study of magnetic materials where quantum fluctuations are strong and give rise unconventional ground states and exotic excitations. Quantum fluctuations arise in low dimensional magnets where magnetic ions with low spin value are coupled by antiferromagnetic interactions into low-dimensional structures, and also in frustrated magnets where the interactions compete with each other and/or with local anisotropies. It is possible to make model materials engineered to exhibit specific quantum features which can then be investigated using neutron scattering. This seminar will present a new frustrated magnet. It is consists of kagome layers of spin-1/2 ions formed from alternating ferromagnetic and antiferromagnetic triangles. The kagome layers are themselves coupled into bilayers by ferromagnetic interactions. Despite having predominantly ferromagnetic interactions and no measureable anisotropy this system fails to order down to the lowest temperatures. Inelastic neutron scattering reveals that the excitations are diffuse at all wavevectors, energies and temperatures, while muon spectroscopy shows slow relaxation suggesting a spin liquid ground state. Possible origins of this behavior will be discussed.

Back to Seminar Home Page



Last modified 12-February-2015 by website owner: NCNR (attn: )