  Optimal performance of thermal machines is reached by suppressing friction.
Friction in quantum thermodynamics results from fast driving schemes that
generate nonadiabatic excitations. The far-from-equilibrium dynamics of quantum
devices can be tailored by shortcuts to adiabaticity to suppress quantum
friction. We experimentally demonstrate friction-free superadiabatic strokes
with a trapped unitary Fermi gas as a working substance and establish the
equivalence between the superadiabatic mean work and its adiabatic value.
