Research at High Magnetic Fields - Activities at the Dresden High Magnetic Field Laboratory

High magnetic fields are one of the most powerful tools available to scientists for the study, modification, and control of the state of matter. The application of magnetic fields, therefore, has become a commonly used instrument in condensed-matter physics. For the observation of many phenomena very high magnetic fields are es-sential. Consequently, the demand for the highest possible magnetic-field strengths is increasing. At the Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden, HLD), that in 2007 has opened its doors for external users, pulsed magnetic fields up to about 72 T are readily available and a European record field of 87.2 T has been reached. The laboratory has set the ambitious goal of reaching 100 T on a 10 ms timescale. As a unique feature, a free-electron-laser facility next door allows high-brilliance radiation to be fed into the pulsed field cells of the HLD, thus making possible high-field magneto-optical experiments in the range 3-250 µm. Cryotech-niques and different sample probes for a broad range of experimental techniques custom designed for the pulsed magnets are available for users. In-house research of the HLD focuses on electronic properties of strongly correlated materials at high magnetic fields. Besides introducing some highlights of the HLD experimental infra-structure, some recent scientific research results will be presented. This includes the determination of the doping-dependent evolution of the Fermi surface of elec-tron-doped high-temperature superconductors by means of Shubnikov de Haas measurements. The observed reconstruction of the Fermi surface gives evidence for the existence of a superlattice potential, the origin of which is still under debate. Fur-ther, the recently found evidence for the Fulde Ferrell Larkin Ovchinnikov state in an organic superconductor will be presented. Emphasis will be laid on such examples where neutron research at high fields might be able to contribute in unravelling topical open questions.