Scientists used the Cutting-edge Photon Source to confirm the erratic properties of this material, which could lead to more effective large-scale computing.
As industrial computing requirements grow, the size and energy requirement of the hardware required to keep up with those needs raises as well. A likely solution to this problem could be found in superconducting materials, which can decrease that energy consumption exponentially. Imagine cooling a massive data center full of continuously running servers down to virtually absolute zero, permitting large-scale computation with unbelievable energy efficiency.
Physicists at the Department of Energy’s (DOE) Argonne National Laboratory have made a discovery that could help permit this more resourceful future. Scientists have found a superconducting material that is exceptionally sensitive to external stimuli, allowing the superconducting properties to be heightened or repressed at will. This allows new prospects for energy-efficient switchable superconducting circuits. The findings were published in Science Advances.
Superconductivity is a quantum mechanical stage of matter in which an electric current can flow through a material with zero resistance. This leads to perfect electronic transport effectiveness. Superconductors are used in the most influential electromagnets for advanced technologies such as magnetic resonance imaging, particle accelerators, fusion reactors and even floating trains. Superconductors have also found uses in quantum computing.
Today’s electronics use semiconducting transistors to rapidly switch electric currents on and off, generating the binary ones and zeroes used in data processing. As these currents essential flow through materials with limited electrical resistance, some of the energy is lost as heat. This is why your computer heats up over time. The low temperatures required for superconductivity, generally more than 200 degrees Fahrenheit below freezing, makes those resources impractical for hand-held devices. However, they could possibly be useful on an industrial scale.
The research team, led by Shua Sanchez of the University of Washington (now at the Massachusetts Institute of Technology), observed an unfamiliar superconducting material with extraordinary tunability. This crystal is made of flat sheets of ferromagnetic europium atoms inserted between superconducting sheets of iron, cobalt and arsenic atoms. Finding ferromagnetism and superconductivity collectively in nature is very rare, according to Sanchez, as one stage usually overpowers the other.
It is essentially a very uncomfortable condition for the superconducting layers, as they are impaled by the magnetic fields from the adjacent europium atoms, Sanchez said. This deteriorates the superconductivity and results in a finite electrical resistance.
To comprehend the collaboration of these phases, Sanchez spent a year as a resident at one of the nation’s foremost X-ray light sources, the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne. While there he was assisted by DOE’s Science Graduate Student Study program. Working with physicists at APS beamlines 4-ID and 6-ID, Sanchez established a comprehensive characterization platform capable of penetrating microscopic details of complex materials.
Using a blend of X-ray procedures, Sanchez and his collaborators were able to demonstrate that applying a magnetic field to the crystal can reorient the europium magnetic field lines to run corresponding to the superconducting layers. This eliminates their antagonistic properties and causes a zero-resistance state to emerge. Using electrical dimensions and X-ray scattering techniques, researchers were able to confirm that they could regulate the behavior of the material.
The nature of autonomous parameters governing superconductivity is quite captivating, as one could map out a comprehensive method of directing this effect, said Argonne’s Philip Ryan, a co-author on the paper. This possible posits numerous captivating ideas together with the ability to control field sensitivity for quantum devices.
The team then applied pressures to the crystal with fascinating results. They found the superconductivity could be either enhanced enough to overwhelmed the magnetism even without re-orienting the field or weakened enough that the magnetic reorientation can no longer produce the zero-resistance state. This extra parameter permits for the material’s sensitivity to magnetism to be measured and modified.
This material is stimulating because you have a close rivalry between numerous phases, and by applying a minor stress or magnetic field, you can increase one phase over the other to turn the superconductivity on and off, Sanchez said. The vast majority of superconductors are not nearly as easily switchable.
