Consequences of density-wave order in a staggered Rashba superconductor

Superconductors with local inversion-symmetry breaking can exhibit properties usually associated with non-centrosymmetric systems, such as local mixing of even and odd superconducting order parameters or unusual magnetic response. An example of a system with such local non-centrosymmetricity is a stack of layers with alternating Rashba spin-orbit coupling due to mirror-symmetry breaking with respect to the individual layers. Motivated by recent experiments on the Ce-based superconductor CeRh₂As₂, which were interpreted as showing possible quadrupole-density-wave order, we investigate the effect of density-wave order on the physics related to local inversion-symmetry breaking. In particular, we study how the partial gapping out of the Fermi surface changes the effect of local inversion-symmetry breaking.