Discovery of Dynamical Axion Quasiparticles Opens New Pathways for Dark Matter Detection

On April 16, 2025, researchers published a study titled Observation of the Axion quasiparticle in 2D MnBi Te, detailing the first direct detection of a dynamical Axion quasiparticle (DAQ) in a two-dimensional material. Using ultrafast pump-probe optics on 2D MnBi Te, the team observed coherent oscillations at ~44 GHz, linked to magnon-induced modulation of Berry curvature, with implications for dark matter detection and unconventional quantum technologies.

In 1978, Wilczek and Weinberg proposed the Axion, a boson addressing QCD’s strong CP problem and dark matter. Detection challenges arise due to its weak interactions. In condensed matter, the dynamical Axion quasiparticle (DAQ) emerges as an analogous high-energy particle. Researchers observed DAQ in 2D MnBi Te using ultrafast pump-probe optics, measuring magnetoelectric coupling with sub-picosecond resolution. They detected coherent oscillations at ~44 GHz, induced by antiferromagnetic magnons. The DAQ arises from Berry curvature modulation and enables novel physics like Axion polaritons and electric control of spin polarization. Applications include unconventional light-matter interactions and antiferromagnetic spintronics. Beyond condensed matter, DAQs could detect dark matter Axions in the meV regime, addressing a critical gap in fundamental physics.

In recent years, quantum materials have emerged as a promising field of research, offering new insights into the fundamental properties of matter. Among these, topological materials have garnered significant attention due to their unique electronic properties, which are robust against impurities and defects. One such material, MnBi2Te4, has been identified as a 2D topological axion antiferromagnet, showcasing novel behaviors that could revolutionize electronics and quantum computing.

MnBi2Te4 is distinguished by its ability to exhibit axion electrodynamics, a phenomenon where light interacts with the material in non-linear ways. This interaction has been observed through experiments demonstrating the Kerr effect, a non-linear optical response, which suggests potential applications in advanced optical devices and quantum information processing. Additionally, this material exhibits a quantized magnetoelectric effect, where the coupling between magnetic and electric fields results in precise, quantized responses. These properties are scientifically intriguing and hold practical implications for developing new electronic components with enhanced stability and efficiency.

Recent experiments on MnBi2Te4 have revealed a layer Hall effect, characterized by a quantized response that could pave the way for innovative electronic devices. These findings build upon earlier work in topological materials like Bi2Se3, expanding our understanding of how quantum states can be manipulated and utilized. The ability to observe these effects in a 2D material is particularly exciting, as it opens possibilities for integrating these properties into existing semiconductor technologies. This could lead to the development of more efficient electronic circuits and potentially contribute to the advancement of quantum computing architectures.

The discovery of these unique properties in MnBi2Te4 underscores the potential of quantum materials to transform various technological sectors. By harnessing the quantized responses observed in these materials, researchers could develop new types of sensors, memory devices, and even quantum bits (qubits) for quantum computers. Furthermore, the study of such materials contributes to our broader understanding of topological phases of matter, which are fundamental to advancing condensed matter physics. This knowledge is crucial for designing future technologies that rely on precise control over quantum states.

The research into MnBi2Te4 represents a significant step forward in the field of quantum materials. By uncovering its unique properties and demonstrating practical applications, scientists have opened new avenues for innovation in electronics and computing. As our understanding of these materials deepens, we can anticipate further breakthroughs that will shape the future of technology, offering solutions to some of the most challenging problems in modern science and engineering.