ETH Zurich Researchers Discover New Type of Ferromagnetism in Custom-Engineered Material
Scientists at ETH Zurich have made a groundbreaking discovery in the field of solid-state magnetism. In a custom-engineered moiré material, the researchers have identified a novel form of ferromagnetism that challenges traditional magnetic theories.
The magnetism in this material is based on the alignment of electron spins for the minimization of kinetic energy. This observation offers new insights into quantum effects and solid-state magnetism.
Traditional ferromagnetism is characterized by the alignment of the magnetic moments of electrons in a material, resulting in its permanent magnetic properties. However, the newly discovered form of ferromagnetism in the moiré material occurs through a completely different mechanism.
The custom-engineered material, produced by layering atomically thin layers of two different semiconductor materials, has a two-dimensional periodic potential with a large lattice constant. By applying an electric voltage, the material can be filled with electrons.
This unique moiré material has attracted significant interest in recent years as a platform for investigating quantum effects of strongly interacting electrons. However, little was previously known about its magnetic properties.
To investigate the magnetic properties of the material, the researchers used laser light to measure the polarization of the electron spins. They found that as more electrons were added to the material, it transitioned from a paramagnetic state to a ferromagnetic state.
The sudden onset of ferromagnetism at a specific electron filling led the researchers to suspect a different mechanism at play. Ultimately, they found that the material exhibited ferromagnetism as a result of the alignment of electron spins to minimize kinetic energy.
This type of magnetism had previously only been detected in model systems, making the discovery in the moiré material a significant breakthrough.
Moving forward, the researchers aim to further investigate the parameters of the moiré lattice to determine if the ferromagnetism can be preserved at higher temperatures. This could have important implications for the development of new materials with unique magnetic properties.
The findings of the study have been published in the scientific journal Nature, under the title “Kinetic magnetism in triangular moiré materials.” This research opens up new possibilities for the exploration of quantum effects and the development of next-generation magnetic materials.