Quantum spin liquids: an experimental view
Fabrice Bert (LPS Orsay)
Spin liquids are fascinating states of matter where quantum fluctuations are strong enough to prevent any kind of magnetic ordering down to absolute zero temperature. Spin liquid physics has been for long a rich playground for theoreticians to discover novel quantum states and concepts, often relevant to other fields such as high Tc superconductivity, and there are now several materials realizing such ground states. I will present an experimental investigation with resonance techniques of two of them: a vanadium oxyfluoride compound where the V4+ ions form a unique S = ½ breathing kagome lattice which consists of alternating equilateral triangles, preserving the full frustration of the isotropic model, and the recently discovered Y-kapellasite which realizes an original spatially anisotropic kagome model.