Investigation of Opto‐magnetic Memory Effects in Antiferromagnetic CuMnAs Using Ultrafast Heat Dynamics and Quench Switching

Abstract Solving complex tasks in a modern information‐driven society requires novel materials and concepts for energy‐efficient hardware. Antiferromagnets offer a promising platform for seeking such approaches due to their exceptional features: low‐power consumption and possible high integration density are desirable for information storage and processing or applications in unconventional computing. Among antiferromagnets, CuMnAs stands out for atomic‐level scalable magnetic textures, analogue multilevel storage capability, and the magnetic state's control by a single electrical or femtosecond laser pulse. Using a pair of excitation laser pulses, this work examines functionalities of CuMnAs favorable for information processing, readily incorporating two principles of distinct characteristic timescales. Laser‐induced transient heat dynamics at sub‐nanosecond times represents the short‐term memory and causes resistance switching due to quenching into a magnetically fragmented state. This quench switching, detectable electrically from ultrashort times to hours after writing, reminisces the long‐term memory. The versatility of the principles' combination is demonstrated by antiferromagnetic in‐memory operations. Temporal latency coding is utilized to encode data from a grayscale image into sub‐nanosecond pulse delays. Applying input laser pulses of distinct amplitudes then allows for determining their relative order at 100‐ps timescales. The results open pathways for ultrafast information processing employing antiferromagnetic memory devices.