The Asian Consortium on Computational Materials Science (ACCMS) Global Centre organises the 39th Webinar on the topic “Emergent Phenomena Exploited at Oxide Heterointerfaces for Unconventional Computing” on April 28, 2026.
Prof. Tamalika Banerjee, Professor & Chair of Spintronics, Functional Materials group, Zernike Institute for Advanced Materials, University of Groningen, Netherlands will deliver the webinar. Dr Darwin B Putungan, Institute of Physics, College of Arts and Sciences, University of the Philippines will be the panellist.
Abstract
Classical computing based on von Neumann architecture is limited by a memory bottleneck, high power consumption, and heat dissipation. This is primarily due to the non-colocation of memory and processing units, making the hardware sequential and deterministic. These challenges can be efficiently tackled by processing the information on the signal, similar to what the human brain does. This has spurred the development of alternative, domain-specific computing paradigms beyond the conventional von-Neumann architecture using analogue devices with memristive materials that can collocate memory and processing in the same functional unit.
Several material systems from phase change memory, Mott memories, resistive random access memories, ferroelectrics, and ferromagnets have been actively researched, demonstrating their potential as memristors exhibiting diverse functionalities. In this webinar, I will discuss a popular choice of materials and devices, based on oxide materials, particularly those possessing competing and coexisting ground states. They offer a rich phase space and are ideal candidates, where emergent phenomena arising at their heterointerfaces can be tailored by strain and doping and tuned by external stimuli such as temperature, electric field, and magnetic field.
I will discuss two specific cases: In the first part, I will discuss the areal downscaling of interface memristive devices directly integrated on a semiconducting Nb-doped SrTiO3 (Nb: STO) platform. We show a surprising enhancement in the memristive memory window, while maintaining analog behavior, contrary to expectations. The device designs on such semiconductors allow leveraging electric field effects at edges, increasing the dynamic range in smaller devices with high endurance and low device and cycle variation, down to the smallest devices with readout at low power. In the second part, I will show how we uniquely exploit the entire network of strained films of La0.67Sr0.33MnO3 by engineering the octahedron tilt at the atomic scale, to demonstrate complex biologically plausible brain functionalities such as self-oscillation and integrate and fire neurons. The combination of an intrinsic coupled phase transition in La0.67Sr0.33MnO3 and octahedral distortion due to the textured surface of the LAlO3 substrate leads to multiple negative differential resistance (NDR) regimes in the network, when electrically driven out of thermodynamic equilibrium, at room temperature. By sweeping either voltage or current at room temperature, we find that thermal effects trigger the film toward non-linear transport regimes. By engineering the time dynamics of such metastable phases, we demonstrate voltage-tunable oscillators that dynamically oscillate at variable frequencies (kHz to MHz) and also show how orbital coupling effects, induced by local strain, enrich the phase space of operation of such oscillators. Finally, I will discuss how the time dynamics of the leaky, integrate, and fire neuron network lead to the development of probabilistic bits, useful for ultra-low power stochastic hardware.