Quantum helimagnetism of the frustrated spin 1/2 chain LiCuVO4

Inelastic neutron scattering, susceptibilit y, and high-field magnetization identify LiCuVO4 as a nearest-neighbour ferromagnetic, next-nearest-neigh bour rustrated, quasi-onedimensional helimagnet,whic h is largely influenced by quantum fluctuations. Complementary band structure calculations provide a microscopic model with the correct sign and magnitude of the major exchange integrals. \newline \newline In collaboration with M. Enderle, C. Mukherjee, B. Fak, R. K. Kremer, J.-M. Broto, H. Rosner, S.-L. Drechsler, J. Richter, J. Malek, A. Prokofiev, W. Assmus, H. Rakoto, M. Rheinstadter, \'Ecole Polytechnique F\'ed\'erale de Lausanne.