New Material to Generate More Computing Power and Memory Storage While Using Less Energy

From University of Minnesota

An University of Minnesota team has, for the 1st time, synthesized a thin film of a unique topological semimetal material that has the potential to generate more computing power and memory storage while using less energy.

The researchers were also able to closely study the material, leading to some important findings about the physics behind its unique properties.The study is published in Nature Communications.

As evidenced by the United States’ recent CHIPS and Science Act, there is a growing need to increase semiconductor manufacturing and support research that goes into developing the materials that power electronic devices everywhere. While traditional semiconductors are the technology behind most of today’s computer chips, scientists and engineers are always looking for new materials that can generate more power with less energy to make electronics better, smaller and more efficient.

One such candidate for these new and improved computer chips is a class of quantum materials called topological semimetals. The electrons in these materials behave in different ways, giving the materials unique properties that typical insulators and metals used in electronic devices do not have. For this reason, they are being explored for use in spintronic devices, an alternative to traditional semiconductor devices that leverage the spin of electrons rather than the electrical charge to store data and process information.

In this study, an interdisciplinary team of University of Minnesota researchers were able to synthesize such a material as a thin film – and prove that it has the potential for high performance with low energy consumption.

“This research shows that you can transition from a weak topological insulator to a topological semimetal using a magnetic doping strategy,” said Jian-Ping Wang, senior author of the paper and professor, College of Science and Engineering. “We’re looking for ways to extend the lifetimes for our electrical devices and at the same time lower the energy consumption, and we’re trying to do that in non-traditional, out-of-the-box ways.”

Researchers have been working on topological materials for years, but the U of M team is the first to use a patented, industry-compatible sputtering process to create this semimetal in a thin film format. Because their process is industry compatible, Wang said, the technology can be more easily adopted and used for manufacturing real-world devices.

“Every day we use electronic devices, from our cell phones to dishwashers to microwaves. They all use chips. Everything consumes energy,” said Andre Mkhoyan, senior author of paper and professor, College of Science and Engineering. “The question is, how do we minimize that energy consumption? This research is a step in that direction. We are coming up with a new class of materials with similar or often better performance, but using much less energy.”

Because the researchers fabricated such a high-quality material, they were also able to closely analyze its properties and what makes it so unique.

“One of the main contributions of this work from a physics point of view is that we were able to study some of this material’s most fundamental properties,” said Tony Low, senior author of paper and associate professor, College of Science and Engineering. “Normally, when you apply a magnetic field, the longitudinal resistance of a material will increase, but in this particular topological material, we have predicted that it would decrease. We were able to corroborate our theory to the measured transport data and confirm that there is indeed a negative resistance.”

Low, Mkhoyan, and Wang have been working together for more than a decade on topological materials for next generation electronic devices and systems – this research wouldn’t have been possible without combining their respective expertise in theory and computation, material growth and characterization, and device fabrication.

“It not only takes an inspiring vision but also great patience across the four disciplines and a dedicated group of team members to work on such an important but challenging topic, which will potentially enable the transition of the technology from lab to industry,” Wang said.

This research is supported by SMART, 1 of 7 centers of nCORE, a Semiconductor Research Corporation program, sponsored by National Institute of Standards and Technology. T.P. and D.Z. were partly supported by ASCENT, 1 of 6 centers of JUMP, a Semiconductor Research Corporation program that is sponsored by MARCO and DARPA. This work was partially supported by the University of Minnesota’s Materials Research Science and Engineering Center program. Parts of this work were carried out in the Characterization Facility of the University of Minnesota Twin Cities, which receives partial support from the National Science Foundation through the MRSEC. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the NSF Nano Coordinated Infrastructure Network.

Article: Robust negative longitudinal magnetoresistance and spin–orbit torque in sputtered Pt₃Sn and Pt₃Sn_xFe_1-x topological semimetal

Nature Communications has published an article written by Delin Zhang, Wei Jiang, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, Hwanhui Yun, Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, 55455, USA, Onri Jay Benally, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, Thomas Peterson, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA, Zach Cresswell, Yihong Fan, Yang Lv, Guichuan Yu, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, Javier Garcia Barriocanal, Characterization Facility, University of Minnesota, Minneapolis, MN, 55455, USA, Przemyslaw Wojciech Swatek, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, K. Andre Mkhoyan, Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, 55455, USA, Tony Low, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, and Jian-Ping Wang, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA, Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, 55455, USA, and School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA.

Abstract: “Contrary to topological insulators, topological semimetals possess a nontrivial chiral anomaly that leads to negative magnetoresistance and are hosts to both conductive bulk states and topological surface states with intriguing transport properties for spintronics. Here, we fabricate highly-ordered metallic Pt₃Sn and Pt₃Sn_xFe_1-x thin films via sputtering technology. Systematic angular dependence (both in-plane and out-of-plane) study of magnetoresistance presents surprisingly robust quadratic and linear negative longitudinal magnetoresistance features for Pt₃Sn and Pt₃Sn_xFe_1-x, respectively. We attribute the anomalous negative longitudinal magnetoresistance to the type-II Dirac semimetal phase (pristine Pt₃Sn) and/or the formation of tunable Weyl semimetal phases through symmetry breaking processes, such as magnetic-atom doping, as confirmed by first-principles calculations. Furthermore, Pt₃Sn and Pt₃Sn_xFe_1-x show the promising performance for facilitating the development of advanced spin-orbit torque devices. These results extend our understanding of chiral anomaly of topological semimetals and can pave the way for exploring novel topological materials for spintronic devices.“