Abstract
Progress of silicon-based technology is nearing its physical limit, as the minimum feature size of components is reaching a mere 10 nm. The resistive switching behavior of transition metal oxides and the associated memristor device is emerging as a competitive technology for next-generation electronics. Significant progress has already been made in the past decade, and devices are beginning to hit the market; however, this progress has mainly been the result of empirical trial and error. Hence, gaining theoretical insight is of the essence. In the present work, we report the striking result of a connection between the resistive switching and shock-wave formation, a classic topic of nonlinear dynamics. We argue that the profile of oxygen vacancies that migrate during the commutation forms a shock wave that propagates through a highly resistive region of the device. We validate the scenario by means of model simulations and experiments in a manganese-oxide-based memristor device, and we extend our theory to the case of binary oxides. The shock-wave scenario brings unprecedented physical insight and enables us to rationalize the process of oxygen-vacancy-driven resistive change with direct implications for a key technological aspect—the commutation speed.
- Received 18 November 2014
DOI:https://doi.org/10.1103/PhysRevX.6.011028
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Published by the American Physical Society
Physics Subject Headings (PhySH)
Synopsis
SynopsisWaves That Shock Resistance
Published 15 March 2016
An electric field can launch shock waves that create a fast and nonvolatile resistivity change in transition-metal oxides.
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Popular Summary
In 1965, Gordon Moore published his observation that the number of transistors in an integrated circuit doubles approximately every two years. This trend eventually became known as Moore’s Law and has arguably become a self-fulfilling prophecy that has shaped the modern electronics industry. More than 50 years later, the smallest electronic components are only a mere 10 nm in size. As a result, silicon-based devices are virtually “running out” of atoms, and new “postsilicon” technologies are actively being investigated to enable continued progress. Memristors (resistive random access memories) based on transition metal oxides have accordingly emerged. Here, we establish an unexpected link between the behavior of memristive memory devices and a classic topic of nonlinear dynamical systems: the formation of shock waves.
Despite rapid experimental advances, theoretical progress in understanding the relevant physical processes behind memristors has been scarce. The changing resistance in these devices can be used to encode information. In this study, we use experiments and numerical simulations of a manganese-oxide-based memristor device to demonstrate that the distribution of oxygen vacancy concentration within the material evolves under the action of a strong electric field as a shock wave; its propagation controls the sudden switching phenomena in these devices. Our results should be relevant to a large class of memristors, including binary oxides, and our findings highlight several physical parameters relevant to resistive switching in next-generation devices.
We expect that our findings will make it possible to theoretically rationalize the memory change and single out the key features that control the commutation speed in memristors.
