Lightwave-controlled relativistic plasma mirrors

We report on attosecond-scale control of high-harmonic and fast electron emission from plasma mirrors driven by relativistic-intensity near-single-cycle light waves at a kHz repetition rate. By controlling the waveform of the intense light transient, we reproducibly form a sub-cycle temporal intensity gate at the plasma mirror surface, leading to the observation of extreme ultraviolet spectral continua, characteristic of isolated attosecond pulse (IAP) generation. We also observe the correlated emission of a waveform-dependent relativistic electron beam, paving the way toward fully lightwave-controlled dynamics of relativistic plasma mirrors.