Electrically controlled nonlocal transport in antiferromagnet/superconductor junctions with Rashba spin-orbital coupling

We theoretically investigate nonlocal transport phenomena at an antiferromagnet/normal/superconductor/antiferromagnet junction. Both parallel and antiparallel configurations are considered, with the Néel vector aligned with the z axis in the left antiferromagnet and with the z and - z axes in the right antiferromagnet, respectively. In the parallel configuration, only equal-spin crossed Andreev reflection (CAR) is allowed, as the conventional CAR is forbidden. As the Rashba spin-orbital coupling strength increases in the normal region, the amplitude of equal-spin CAR increases while the amplitude of electron elastic cotunneling (EC) decreases, resulting in equal-spin CAR-dominant nonlocal transport. In the antiparallel configuration, a CAR-dominant nonlocal transport is observed at low Rashba spin-orbital coupling strength, with the conventional CAR process being finite. Furthermore, our results indicate that increasing the staggered sublattice potential enhances the conventional CAR in the parallel configuration, and conversely, in the antiparallel configuration at high Rashba spin-orbital coupling strength, it reduces CAR dominance in favor of EC processes. Therefore, by adjusting the Rashba spin-orbital coupling strength and staggered sublattice potential, CAR-dominant nonlocal transport can be achieved in both the parallel and antiparallel configurations.