# Sub-nanosecond heat-based logic, writing and reset in an antiferromagnetic magnetoresistive memory

## TL;DR

This paper demonstrates a new type of memory device that uses heat pulses to perform logic operations and store information at ultrafast speeds.

## Contribution

The study introduces sub-nanosecond heat-based logic and magnetoresistive memory using an antiferromagnetic material.

## Key findings

- Heat pulses can trigger logic operations and transfer results to a long-term magnetoresistive memory.
- Switching between magnetic states occurs at sub-nanosecond timescales, compatible with GHz electronics.
- The long-term memory can be rapidly reset to its initial state using heat pulses.

## Abstract

Thermal logic aims to create thermal counterparts to electronic circuits. In this work, we investigate experimentally the response of an analog memory device based on a thin film of an antiferromagnetic metal CuMnAs to bursts of heat pulses generated by the absorption of femtosecond laser pulses at room ambient temperature. When a threshold temperature in the heat-based short-term memory of the device is exceeded, the output of the in-memory logic operations is transferred within the same device to a long-term memory, where it can be retrieved at macroscopic times. The long-term memory is based on magnetoresistive switching from a reference low-resistive uniform magnetic state to high-resistive metastable nanofragmented magnetic states. The in-memory heat-based logic operations and the conversion of the outputs into the electrically-readable long-term magnetoresistive memory were performed at sub-nanosecond time scales, making them compatible with the GHz frequencies of standard electronics. Finally, we demonstrate the possibility of rapidly resetting the long-term memory to the reference low-resistive state by heat pulses.

The online version contains supplementary material available at 10.1186/s43074-025-00207-1.