  We report on attosecond-scale control of high-harmonic and electron emission
from plasma mirrors driven by relativistic-intensity near-single-cycle
lightwaves at 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 generation. We
also observe the correlated emission of a waveform-dependent relativistic
electron beam, paving the way towards fully lightwave-controlled dynamics of
relativistic plasma mirrors.
