Pulsed Field Science Highlights
Magic Gap Ratio at the "BCS Superconducting to Bose-Einstein Condensate" Crossover in the High-Tc Cuprates
A defining experimental signature of a crossover in the strength of the pairing interactions from the weak coupling BCS to the strong coupling Bose-Einstein condensation limit has been discovered in high temperature superconductors.
Three complementary measurements in intense magnetic fields shed light on a very unusual material that behaves like a metal, but does not conduct electricity!
Generally, light transmission is symmetrical - it's the same if you shine a light through a material forward or backwards. Using powerful pulsed fields, researchers revealed one-way transparency in a nickel-tellurium-oxygen based material showing that light flows one way across the telecom range – a finding that opens the door to exciting new photonics applications.
A new class of correlated quasiparticle states discovered in a multi-valley semiconductor using optical absorption measurements in pulsed magnetic fields. This new type of multi-particle state results when excitons interact simultaneously with multiple electron reservoirs that are quantum-mechanically distinguishable by virtue of having different spin and/or valley quantum numbers.
In everyday life, phase transitions - like when water boils and turns into steam or freezes and becomes ice - are caused by changes in temperature. Here, very high magnetic fields are used to reveal a quantum phase transition not caused by temperature, but instead driven by quantum mechanics upon changing the concentration of electrons, work that could hold critical clues that explain high-temperature superconductivity.
Scientists at the Pulsed Field Facility recently found that applying an intense magnetic field to the mineral atacamite (a "frustrated" quantum magnet) yields unusual behavior associated with a novel state of matter known as quantum spin liquid.
Duplex magnets use two independent coils powered by capacitor banks to reduce the driven voltages and provide more design flexibility to maximize the generated magnetic fields. The Pulsed Field Facility developed such a duplex magnet to generate magnetic field up to 76.8 Tesla using existing 16-kV, 4-MJ capacitor bank (cap-bank) that now provides important information on a new state of matter in YbB12.
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.
Interactions between electrons underpin some of the most interesting – and useful -- effects in materials science and condensed-matter physics. This work demonstrates that, in the new family of so-called "monolayer semiconductors" that are only one atomic layer thick, electron-electron interactions can lead to the sudden and spontaneous formation of a magnetized state, analogous to the appearance of magnetism in conventional materials like iron.
Superconductors conduct large amounts of electricity without losses. They are also used to create very large magnetic fields, for example in MRI machines, to study materials and medicine. Here, researchers developed a fast, new "smart" technique to measure how much current a superconductor can carry using very high pulsed magnetic fields.
Materials with magnetoelectric coupling - a combination of magnetic and electric properties - have potential applications in low-power magnetic sensing, new computational devices and high-frequency electronics. Here, researchers find a new class of magnetoelectric materials controlled by spin state switching.
Researchers demonstrate a new record magnetoresistance in graphene by improving the contacting method, which helps improve our understanding of the material and can be useful in future sensors, compasses and other applications.
Studies of uranium ditelluride in high magnetic fields show superconductivity switching off at 35 T, but reoccurring at higher magnetic fields between 40 and 65 T.
Research on doped SrCu2(BO3)2 shows anomalies in the magnetization.
In Sr3NiIrO6 vibrations in the crystal lattice (phonons) play an important role in its intriguing magnetic properties that result in a very high coercive field of 55 T. Using a combination of pulsed and DC magnetic fields coupled with magnetization and far-infrared spectroscopy, researchers were able to conclusively link the phonons to the magnetic behavior.
Using intense pulsed magnetic fields and measurements at low temperatures, MagLab users have found evidence of a long-sought “spin liquid” in terbium indium oxide (TbInO3)
Pulsed magnets are designed to operate near their structural limits to be able to generate extremely high magnetic fields. The coils have a limited life expectancy and thus need to be replaced on occasion. Fabrication of these large coils are now being done at the MagLab where advanced nondestructive examinations can be performed. Because of more rigorous quality controls and improvements in high-strength conductors and reinforcement materials, the lifetime of these coils can be extended.
Weyl metals such as tantalum arsenide (TaAs) are predicted to have novel properties arising from a chirality of their electron spins. Scientists induced an imbalance between the left- and right-handed spin states, resulting in a topologically protected current. This was the first time this phenomenon, known as the chiral anomaly, has been observed.
Scientists used high magnetic fields and low temperatures to study crystals of URu2–xFexSi2. Using these conditions, they explored an intriguing state of matter called the "hidden order phase" that exhibits emergent behavior. Emergent behavior occurs when the whole is greater than the sum of its parts, meaning the whole has exciting properties that its parts do not possess; it is an important concept in philosophy, the brain and theories of life. This data provide strict constraints on theories of emergent behavior.
Analogous to the unique spectral fingerprint of any atom or molecule, researchers have measured the spectrum of optical excitations in monolayer tungsten diselenide (WSe2), which is a member of a new family of ultrathin semiconductors that are just one atomic layer thick.