Ultra-low-energy synaptic-like optical data storage mediated by photo-switchable upconversion states

The data increase necessitates high-capacity, low-energy optical data storage. Bridging the memory gap between units and processors requires techniques and materials mimicking the efficiency of the human brain’s memory based on synaptic plasticity. Optical techniques show promise, yet energy-efficient optical data storage compels advanced media. Upconversion nanoparticles are luminescent nanomaterials for high-capacity, low-energy optical data storage. We used upconversion nanoparticles for ultra-low-energy optical data storage with synaptic-like behaviour by switching upconversion states under low light power irradiation. We achieved features with sub-nanojoule-level energy consumption and synaptic-like functions of the human brain’s memory, enabling short-term and long-term memory.