Hexagonal lattices, like the ones present in Graphene and transition metal dichalcogenides (TMDs), present two equivalent points in the Brillouin zone where local extrema of the band structure take place. These points are known as valleys. In presence of localized defects and local short-range potentials electrons moving through different valleys can couple increasing scattering events and reducing the quality of the transport properties of the material. However, the presence of spin-orbit and magnetism can brake the valley degeneracy reducing dramatically the inter-valley scattering. In Spin-Waals we are studying different heterostructures combining TMDs and 2D magnetic materials to find suitable combinations giving rise to a giant valley splitting which may find applications in spintronics and quantum computing.
Magnons are spin excitations that occurs in magnetic materials. These quasi-particles behave like bosons and can be used to transport spin information along magnetic materials without electrons. This decreases dramatically the energy consumption and reduces Joule heating due to a reduction in the scattering events. Magnons can be excited using microwaves or laser beams through phonon-magnon coupling. Very recent experiments have shown that magnons in 2D magnetic materials can be easily excited enhancing the spin transport in ferromagnetic insulators. At spin-Waals group we are interested in studying how proximity effects in van der Waals heterostructures can modify the magnon dispersion and the phonon-magnon coupling to find the best candidates for future magnonics devices.
Twistronics has become a very hot topic since the discovery of superconductivity in magic angle twisted bilayer graphene. In 2D magnetic materials, twisted samples give rise to different stacking patterns modifying locally the interlayer exchange interaction. This allows for the formation of magnetic domains in twisted magnets and the emergence of non-trivial spin textures like spin spirals and skyrmions. In the Spin-Waals group we want to study the impact of Moiré magnetic lattices in the magnon dispersion and localization. Similarly to the twisted Graphene electronic bands, magnons in twisted magnets become flat which may increase their localization which can be useful for information storage nanodevices.