Mind and Machine

An X-ray step towards superfast nanoelectronics

When a material with magnetic properties, constructed from appropriately selected layers, is illuminated by a pulse from an X-ray laser, it instantly demagnetizes. This phenomenon, so far poorly understood, could in the future be used in nanoelectronics, to build, for example, ultrafast magnetic switches. An important step toward this goal is a new simulation tool developed by a Polish-German-Italian team of scientists as part of a joint research project between the European XFEL and IFJ PAN.

No information-processing device can operate at a speed faster than that at which the physical phenomena underlying its operation occur. That is why physicists continue to seek phenomena that run on increasingly shorter spatial and temporal scales, yet can be controlled relatively easily. One promising research direction seems to be the demagnetization process of ferromagnetic multilayer materials initiated by ultrafast X-ray laser pulses.

A team of physicists from Poland, Germany and Italy, working at the European XFEL facility and at the DESY facility in Hamburg, can now boast a significant achievement in this field: Their study in npj Computational Materials presents the first tool that makes it possible to simulate the progress of X-ray-induced demagnetization. Scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow are an important part of the team.

Scientists used the Advanced Photon Source to watch a nonliving material mimic behavior associated with learning, paving the way for better artificial intelligence.

Scientists looking to create a new generation of supercomputers are looking for inspiration from the most complex and energy-efficient computer ever built: the human brain.

In some of their initial forays into making brain-inspired computers, researchers are looking at different nonbiological materials whose properties could be tailored to show evidence of learning-like behaviors. These materials could form the basis for hardware that could be paired with new software algorithms to enable more potent, useful and energy-efficient artificial intelligence (AI).

In a new study led by scientists from Purdue University, researchers have exposed oxygen deficient nickel oxide to brief electrical pulses and elicited two different electrical responses that are similar to learning. The result is an all-electrically-driven system that shows these learning behaviors, said Rutgers University professor Shriram Ramanathan. (Ramanathan was a professor at Purdue University at the time of this work.) The research team used the resources of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory.

A little nudge

All it takes is a few taps on the side of this vial and—like magic—a ring of fluffy white solid suddenly appears inside, seemingly out of nowhere But a closer look reveals a few drops of a clear, colorless liquid, pooled almost invisibly at the bottom of the vial, that rapidly crystallize under when the vial is tapped.

The stuff in the vial is a ligand that Jaime Martin, a postdoc in Cristina Nevado’s group at the University of Zurich, synthesized as part of his research quest to make a library of stable gold(III) complexes and study their properties and reactivity. Gold(III) tends to undergo reduction easily, and a good ligand is essential for keeping the metal happy in the desired oxidation state. Martin says that most of the ligands he makes are liquids after purification, but the higher molecular weight ones can crystallize under the right conditions—given a little nudge. It’s “very very satisfying” to see the solid pop up under vacuum, he says.—Brianna Barbu

Credit: Jaime Martin. Follow him on Twitter @Jaime_Chem.

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