A team of physicists has discovered a new type of superconducting material that is uniquely tunable in response to external stimuli and could advance the development of energy-efficient computing and quantum technologies. This breakthrough, achieved through advanced research technology, enables unprecedented control of superconducting properties and has the potential to revolutionize large-scale industrial applications. The material is expected to be used in superconducting circuits for next-generation industrial electronics.
As industrial computing needs grow, so do the size and power consumption of the hardware required to meet those needs. Superconducting materials are a possible solution to this problem, which can reduce energy consumption exponentially. Just imagine cooling a giant data center filled with constantly running servers to near absolute zero to enable large-scale computing with astonishing energy efficiency.
Breakthrough in superconducting research
Physicists at the University of Washington and DOE's Argonne National Laboratory have made a discovery that could help realize this more efficient future. Researchers have discovered a superconducting material that is particularly sensitive to external stimuli and can enhance or suppress its superconducting properties at will. This brings new opportunities for energy-efficient switchable superconducting circuits. The paper was published in Science Advances.
Superconductivity is a quantum mechanical phase of matter in which electric current can flow through a material with zero resistance. This results in perfect electron transfer efficiency. Superconductors are used in the most powerful electromagnets in advanced technologies such as magnetic resonance imaging, particle accelerators, nuclear fusion reactors and even levitating trains. Superconductors can also be used in quantum computing.
Challenges and innovations
Today's electronics use semiconductor transistors to quickly switch current on and off, producing the binary ones and zeros used in information processing. Because these currents must flow through materials with finite resistance, some of the energy is wasted in the form of heat. This is why computers heat up over time. The temperatures required to superconduct are very low, often more than 200 degrees Fahrenheit below freezing, so these materials are not suitable for use in handheld devices. However, one can imagine their use on an industrial scale.
A research team led by Shua Sanchez of the University of Washington studied an unusual superconducting material with extraordinary tunability. The crystal consists of flat slabs of ferromagnetic europium atoms sandwiched between superconducting layers of iron, cobalt and arsenic atoms. Sanchez said it is extremely rare to find both ferromagnetism and superconductivity in nature because one phase usually overpowers the other.
"This is actually a very uncomfortable situation for the superconducting layers because they are penetrated by the magnetic field of the surrounding europium atoms, which weakens the superconductivity and leads to a finite resistance," Sanchez said.
Advanced research technologies and results
To understand the interactions between these stages, Sanchez spent a year interning at the nation's leading X-ray light source, the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne. There he was supported by the Department of Energy's Science Graduate Research Program. Sanchez collaborated with physicists at the APS4-ID and 6-ID beamlines to develop a comprehensive characterization platform capable of probing microscopic details in complex materials.
Using a combination of X-ray techniques, Sanchez and his collaborators showed that applying a magnetic field to the crystal can adjust the direction of the europium magnetic field lines so that they are parallel to the superconducting layer. This eliminates the antagonism between them and results in a zero-resistance state. Using electrical measurements and X-ray scattering techniques, the scientists were able to demonstrate that they could control the material's behavior.
"The nature of the independent parameters that control superconductivity is quite fascinating because one can map out the complete way to control this effect," said paper co-author Philip Ryan of Argonne University. "This potential raises several fascinating ideas, including the ability to tune field sensitivity for quantum devices."
The team then applied stress to the crystal, and the results were very interesting. They found that without reorienting the magnetic field, superconductivity can be boosted enough to overcome magnetism, or weakened to the point where reorienting the magnetic field can no longer produce a zero-resistance state. This additional parameter allows control and customization of the material's susceptibility to magnetism.
"This material is exciting because you can have multiple phases in close competition, and by applying a small stress or magnetic field, you can make one phase stronger than another, turning superconductivity on or off," Sanchez said. "Most superconductors are not switched that easily."
Compiled source: ScitechDaily