Picosecond transfer from short-term to long-term memory in analog antiferromagnetic memory device

Previous experiments in compensated magnets have demonstrated a potential for approaching the limit of fastest and least-dissipative operation of digital memory bits. However, the analog route has been virtually unexplored at (sub)ps time scales. In this paper, we report on experimental separation of heat-related and quench-switching-related resistance signal dynamics induced at room temperature by a single femtosecond-laser-pulse in memory devices made from a metallic antiferromagnetic CuMnAs. We show that the heat-related dynamics, on picosecond to hundreds of nanoseconds time scales, can be used as a short-term memory where information about input stimuli, represented by laser-pulses, is stored temporarily. When the quench-switching threshold is reached, information is transferred to the device's variable resistance, serving as a long-term memory, with time components of 10 ms and 10 s. The potentially appealing features of the heat-based memory for several distinct research fields, including bio-inspired analogue devices and heat-based logic, are also discussed.