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.