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arXiv · 2509.22767

Conductance-dependent Photoresponse in a Dynamic SrTiO3 Memristor for Biorealistic Computing

Christoph Weilenmann·Hanglin He·Marko Mladenović·Till Zellweger·Kevin Portner·Klemens Bauer·Guillaume Bellec·Mathieu Luisier·Alexandros Emboras
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Abstract

Modern computers perform pre-defined operations using static memory components, whereas biological systems learn through inherently dynamic, time-dependent processes in synapses and neurons. The biological learning process also relies on global signals - neuromodulators - who influence many synapses at once depending on their dynamic, internal state. In this study, using optical radiation as a global neuromodulatory signal, we investigate nanoscale SrTiO3 (STO) memristors that can act as solid-state synapses. Via diverse sets of measurements, we demonstrate that the memristor's photoresponse depends on the electrical conductance state, following a well-defined square root relation. Additionally, we show that the conductance decays after photoexcitation with time constants in the range of 1 - 10 s and that this effect can be reliably controlled using an electrical bias. These properties in combination with our device's low power operation (< 1pJ per optical pulse) and small measurement variability may pave the way for space- and energy-efficient implementations of complex biological learning processes in electro-optical hardware.

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Christoph Weilenmann, Hanglin He, Marko Mladenović, Till Zellweger, Kevin Portner, Klemens Bauer, Guillaume Bellec, Mathieu Luisier, Alexandros Emboras. 2025-09-26. Conductance-dependent Photoresponse in a Dynamic SrTiO3 Memristor for Biorealistic Computing. https://arxiv.org/abs/2509.22767

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