摘要： Light beams carrying orbital angular momentum (OAM) are well known due to their powerful capabilities for applications in many fields, such as optical communications, microscopy, quantum optics, quantum information or microparticle manipulation. In this work we introduce a new class of light beams that possess a unique property associated with a temporal variation of their OAM: the self-torque of light. Despite the recent progress in the generation of designer ultrafast light waveforms with OAM, up to now there is no evidence for the creation of pulses with time-dependent OAM in any spectral regime. We define the self-torque of light as ?ξ = ?d?(t)/dt, where ??(t) represents the inherent time-variation of a beam’s OAM. This definition has an analogy with mechanical systems that self-induce a variation of their angular momentum. Here, we theoretically predict, and experimentally validate, that self-torque can be naturally imprinted onto extreme-ultraviolet (EUV) beams through the extreme nonlinear process of high-harmonic generation (HHG). By driving HHG with two time-delayed infrared pulses with different OAM, EUV pulses are produced with an inherent, time-varying OAM. Moreover, the dynamical process of HHG imprints a continuous OAM distribution that varies on the attosecond timescale, where all intermediate OAM components are present. The excellent agreement between our simulations and our experimental characterization confirms the creation of EUV self-torqued beams. We show that the properties of the driving pulses—duration and time delay—provide for exquisite control of the amount of self-torque imprinted into a light pulse. This new class of beams can serve as a unique tool for imaging magnetic and topological excitations, for launching selective excitation of quantum matter, and for nano-manipulation on unprecedented time and length scales.