What if computers could learn to reconfigure their circuits when presented with new information?
A multi-institutional team, including the U.S. Department of Energy’s (DOE) Argonne National Laboratory, has developed a material with which computer chips can be designed to do just that. It does so by mimicking functions in the human brain with so-called “neuromorphic” circuits and computer architecture. The team was led by Shriram Ramanathan, a professor at Purdue University.
“Human brains can actually change as a result of learning new things. We have now created a device for machines to reconfigure their circuits in a brain-like way.” — Subramanian Sankaranarayanan, Nanoscience and Technology division
“Human brains can actually change as a result of learning new things,” said Subramanian Sankaranarayanan, a paper co-author with a joint appointment at Argonne and the University of Illinois Chicago. “We have now created a device for machines to reconfigure their circuits in a brain-like way.”
With this ability, artificial intelligence-based computers could carry out complex tasks faster and more accurately, with much less energy expended. One example is in interpreting complex medical images. A more futuristic example would be autonomous vehicles and robots in space that could reprogram their circuits based on experience.
The key material in the new device consists of neodymium, nickel and oxygen and is referred to as a perovskite nickelate (NdNiO3). The team infused this material with hydrogen and attached electrodes to it that allow electrical pulses to be applied at different voltages.
“How much hydrogen is in the nickelate, and where it is, changes the electronic properties,” Sankaranarayanan said. “And we can change its location and concentration with different electrical pulses.”
“This material has a many-layered personality,” added Hua Zhou, a paper co-author and Argonne physicist. “It has the two usual functions of every-day electronics -- the turning on and blocking of electrical current as well as the storing and release of electricity. What’s really new and striking is the addition of two functions similar to the separate behavior of synapses and neurons in the brain.” A neuron is a single nerve cell that connects with other nerve cells via synapses. Neurons initiate sensing of the external world.
For its contribution, the Argonne team carried out computational and experimental characterization of what happens in the nickelate device under different voltages. To that end, they relied on DOE Office of Science user facilities at Argonne: the Advanced Photon Source, Argonne Leadership Computing Facility and Center for Nanoscale Materials.
The experimental results demonstrated that simply altering the voltage controls the movement of hydrogen ions within the nickelate. A certain voltage concentrates hydrogen at the nickelate center, spawning neuron-like behavior. A different voltage shuttles that hydrogen out of the center, yielding synapse-like behavior. At still different voltages, the resulting locations and concentration of the hydrogen elicit the on-off currents of computer chips.
“Our computations revealing this mechanism at the atomic scale were super intensive,” said Argonne scientist Sukriti Manna. The team relied upon the computational horsepower of not only the Argonne Leadership Computing Facility, but also the National Energy Research Scientific Computing Center, a DOE Office of Science user facility at Lawrence Berkeley National Laboratory.
Confirmation of the mechanism came, in part, from experiments at beamline 33-ID-D of the Advanced Photon Source.
“Over the years we have had a very productive partnership with the Purdue group,” Zhou said. “Here, the team determined exactly how atoms arrange within the nickelate under different voltages. Especially important was tracking the material’s response at the atomic scale to the movement of hydrogen.”
With the team’s nickelate device, scientists will work to create a network of artificial neurons and synapses that could learn and modify from experience. This network would grow or shrink as it is presented with new information and would thus be able to work with extreme energy efficiency. And that energy efficiency translates into lower operational cost.
Brain-inspired microelectronics with the team’s device as a building block could have a bright future. This is especially so because the device can be made at room temperature by techniques compatible with semiconductor industry practices.
This research has been reported in a recent Science article, “Reconfigurable perovskite nickelate electronics for artificial intelligence.” Besides Sankaranarayanan, Manna, and Zhou, another Argonne contributor is Suvo Banik. In addition to Ramanathan, Purdue contributors include Hai-Tian Zhang, Tae Joon Park, Qi Wang, Sandip Mondal, and Haoming Yu. Also participating were Pennsylvania State University, Santa Clara University, Brookhaven National Laboratory, University of Georgia, Portland State University and University of Illinois Chicago.
Argonne-related work was supported by the DOE Office of Basic Energy Sciences, as well as the Air Force Office of Scientific Research and National Science Foundation.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
The Argonne Leadership Computing Facility provides supercomputing capabilities to the scientific and engineering community to advance fundamental discovery and understanding in a broad range of disciplines. Supported by the U.S. Department of Energy’s (DOE’s) Office of Science, Advanced Scientific Computing Research (ASCR) program, the ALCF is one of two DOE Leadership Computing Facilities in the nation dedicated to open science.
About the Advanced Photon Source
The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.
This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.