  Particle acceleration and heating at mildly relativistic magnetized shocks in
electron-ion plasma are investigated with unprecedentedly high-resolution
two-dimensional particle-in-cell simulations that include ion-scale shock
rippling. Electrons are super-adiabatically heated at the shock, and most of
the energy transfer from protons to electrons takes place at or downstream of
the shock. We are the first to demonstrate that shock rippling is crucial for
the energization of electrons at the shock. They remain well below
equipartition with the protons. The downstream electron spectra are
approximately thermal with a limited supra-thermal power-law component. Our
results are discussed in the context of wakefield acceleration and the
modelling of electromagnetic radiation from blazar cores.
