To account for material slips at microscopic scale, we take deformation mappings as SBV functions $$\varphi $$
φ
, which are orientation-preserving outside a jump set taken to be two-dimensional and rectifiable. For their distributional derivative $$F=D\varphi $$
F
=
D
φ
we examine the common multiplicative decomposition $$F=F^{e}F^{p}$$
F
=
F
e
F
p
into so-called elastic and plastic factors, the latter a measure. Then, we consider a polyconvex energy with respect to $$F^{e}$$
F
e
, augmented by the measure $$|\textrm{curl}\,F^{p}|$$
|
curl
F
p
|
. For this type of energy we prove the existence of minimizers in the space of SBV maps. We avoid self-penetration of matter. Our analysis rests on a representation of the slip system in terms of currents (in the sense of geometric measure theory) with both $$\mathbb {Z}^{3}$$
Z
3
and $$\mathbb {R}^{3}$$
R
3
valued multiplicity. The two choices make sense at different spatial scales; they describe separate but not alternative modeling options. The first one is particularly significant for periodic crystalline materials at a lattice level. The latter covers a more general setting and requires to account for an energy extra term involving the slip boundary size. We include a generalized (and weak) tangency condition; the resulting setting embraces gliding and cross-slip mechanisms. The possible highly articulate structure of the jump set allows one to consider also the resulting setting even as an approximation of climbing mechanisms.