Thomas La Grange
Engineering the wavefunction of fundamental particles recently allowed to impart orbital angular momentum to photons, electrons, neutrons and even atoms. These so-called vortex beams hold promise for diagnosing and controlling materials properties ranging from electronic, magnetic, and even nuclear. Here we show that vortex light beams can control the sense of rotation of a skyrmion lattice (SkL), providing a unique handle for the deterministic control of the magnetization in a topological magnet. While circularly polarized light has been shown before to induce the rotation of a skyrmion lattice, without control on the handiness of the rotation, individual femtosecond pulses of light carrying single quanta of orbital angular momentum (OAM) impinging on a nano-film of Cu2OSeO3 are shown to rotate the skyrmion lattice according to their handiness. The microscopic vortex light-matter interaction at the basis of this new effect is not yet will understood. This presentation aims to highlight the potential of OAM beams to control spin dynamics in materials and to have an open a dialogue within the community regarding possible mechanisms responsible for interesting observations.