A scientist combines high magnetic fields with ultra short laser pulses to probe the mysteries of photosynthesis.
Two researchers play with nanostructures in a fun, fertile physics playground: the space between two things.
The work by Dagan et. al. explores the emergence and coexistence of superconductivity and magnetism at the interface between insulating, non-magnetic LaAlO3 and SrTiO3 nanowires at low temperatures. The effect of the antiparallel magnetic order on the resistance of the 50 nm wide patterned wires follows the form of giant magnetoresistance (GMR) at low applied magnetic fields.
Here we study the microstructural and transport properties of Co-Ba122 thin films in which secondary non-superconducting phases have been introduced during film growth in two different ways: first by using a Co-Ba122 target with a small amount of oxygen, second by alternating two different targets: a clean CoBa122 and an undoped Ba122 target.
After a series of frustrating failures, a team of MagLab scientists realized they were tackling the wrong problem.
In a well-run library, an authoritative "Sssshhhh!!" will quiet things down in a jiffy.
At the MagLab, we value our quiet time, too — especially in the Millikelvin Facility, home to some of our most sensitive equipment and experiments. But we need more than a pursed-lipped librarian: We need a building designed from top to bottom to shield its magnets from the noise of external electromagnetic (EM) radiation.
And we're about to get it. We recently broke ground on an extension to the existing Millikelvin Facility, currently home to three superconducting magnets that scientists use for experiments at ultra-low temperatures.
The 1,640-square-foot addition will house two new superconducting magnets, including the much-anticipated 32 tesla all-superconducting magnet. Designed and built at the MagLab, the 32 T will shatter existing records for field strength in superconducting magnets when it comes online later this year.
The design of the $1.2-million Millikelvin addition reflects the many lessons learned from two decades operating the existing facility, said MagLab Facility Director John Kynoch. The walls of the windowless structure will include a layer of copper, effectively creating an EM radiation-blocking Faraday cage. The magnets will be positioned safely below ground, surrounded by concrete reinforced with non-magnetic rebar. The extension's high-quality electrical grounds will be separate from the main building.
Even the LED lighting and air conditioning are designed to minimize noise, air currents and temperature fluctuations that could disturb finicky experiments, said Tim Murphy, who oversees Millikelvin as director of the DC Field Facility.
"If your building temperature swings wildly," said Murphy, "you can see that in your data."
Years in the planning, the addition is designed not just to house magnets, but to do science.
"We're treating the building as part of the instrument," said Murphy, "not just some place you put the instrument."
The new building is slated for completion in the spring of 2017.
Text by Kristen Coyne. Photo by Stephen Bilenky.
How researchers use powerful magnets to learn about materials.
Niobium diselenide is found to retain its superconductivity even under very high magnetic fields.