This highlight focuses on the development of new thermometry required to study quantum materials and phenomena in high magnetic fields and at ultralow temperatures. The team has demonstrated that exceedingly small quartz tuning forks bathed in liquid 3He maintain a constant calibration that is magnetic field independent, thereby opening the use of these devices as new sensors of the response of quantum systems.
A new method to study how the nuclei of atoms “communicate” with one another in the presence of unpaired electron spins has been developed at the MagLab. Known as hyperpolarization resurgence (HypRes), this method benefits and expands the application of a revolutionary technique known as dynamic nuclear polarization (DNP), which provides enormous signal enhancements in nuclear magnetic resonance (NMR) experiments.
High-resolution electron magnetic resonance studies of the spin-wave spectrum in the high-field phase of the multiferroic Bismuth ferrite (BiFeO3) reveal direct evidence for the magnetoelastic coupling through a change in lattice symmetry from rhombohedral to monoclinic. This study provides important information for designing future spintronics devices based on BiFeO3.
A pane of window glass and a piece of quartz are both are transparent to light, but their atomic structure is very different. Quartz is crystalline at the atomic level while window glass is amorphous. This can also occur with magnetism at the atomic level in solids containing magnetic states such as antiferromagnetism (ordered) and spin-glass (disorded). This work describes the interaction (exchange bias) between ordered and disordered magnetic states and how the magnetic properties of the material are altered as a result.
High field superconductor magnets greater than 10 T made from brittle Nb3Sn superconducting wires need special attention to their assembly, strength and endurance. This new study of damage in Nb3Sn superconducting wire from prototype accelerator coils built at CERN provides a path to designing better superconductor cables for the next generation of higher field accelerator magnets.
Researchers based at four-year colleges and universities outside of the Research-1 (R1) tier face more obstacles to performing research than their colleagues from R1 universities or national laboratories with robust research infrastructures. Recognizing the need to bridge this infrastructure gap, the MagLab's DC Field Facility expanded access by adding two low-field magnet systems. These "on-ramp" systems facilitate critical access to materials research instrumentation by faculty and students from non-R1 institutions.
An exciting advance of interest to future molecular-scale information storage. By using the uniquely high frequency Electron Magnetic Resonance techniques available at the MagLab, researchers have found single molecule magnets that feature direct metal orbital overlap (instead of weak superexchange interactions), resulting in behavior similar to metallic feromagnets that is far more suitable to future technologies than previous molecular magnets.
Physics does not yet know why copper-based superconductors (cuprates) conduct electrical current without dissipation at unprecedentedly high temperatures. Ultra high magnetic fields are used here to suppress superconductivity in a cuprate near absolute zero temperature, revealing an underlying transition to an electronic phase that might be the cause of the superconductivity.
Three non-destructive testing methods are developed for inspection of high strength, high conductivity wires which are used to wind ultra-high field pulsed magnets at the National MagLab. We expect the lifetime of future magnets to exceed those of past magnets due to these improvements in quality control.
This highlight reports on the still poorly understood transition to an electron crystalline state (the Wigner crystal) in a two-dimensional system at extremely low densities, observable at low temperatures as a function of magnetic field. This experiment finds a surprising stabilization of the Wigner crystal arising from magnetic-field-induced spin alignment. Such electrically-delicate samples require the ultra-low-noise environment and experimental techniques available at the High B/T facility.