  We perform experimental and numerical studies of a granular system under
cyclic-compression to investigate reversibility and memory effects. We focus on
the quasi-static forcing of dense systems, which is most relevant to a wide
range of geophysical, industrial, and astrophysical problems. We find that
soft-sphere simulations with proper stiffness and friction quantitatively
reproduce both the translational and rotational displacements of the grains. We
then utilize these simulations to demonstrate that such systems are capable of
storing the history of previous compressions. While both mean translational and
rotational displacements encode such memory, the response is fundamentally
different for translations compared to rotations. For translational
displacements, this memory of prior forcing depends on the coefficient of
static inter-particle friction, but rotational memory is not altered by the
level of friction.
