Perfect in-plane CrI3 spin-valve driven by photogalvanic effect

Out-of-plane spin tunneling through the two-dimensional (2D) van der Waals ${\mathrm{CrI}}_{3}$ multilayer has recently been deeply explored, and giant magnetoresistance has been achieved in various ${\mathrm{CrI}}_{3}$ magnetic tunneling junctions (MTJs) via the control of interlayer antiferromagnetic coupling by both magnetic and electric fields. In contrast, knowledge of the in-plane spin-transport properties of 2D ${\mathrm{CrI}}_{3}$ is currently very limited. Here, based on quantum transport simulations, we study the in-plane transport properties of the photocurrent in a ${\mathrm{CrI}}_{3}$ MTJ with a bilayer/monolayer/bilayer configuration. The photogalvanic effect (PGE) is induced under vertical illumination of elliptically polarized light, giving rise to a robust photocurrent in a broad visible range at zero bias. A perfect spin-valve effect can be achieved with a magnetoresistance of 100% for some photon energies with an appropriate light helicity. Moreover, the PGE photocurrent for the antiparallel configuration is enhanced, as compared to the parallel configuration due to the increased device asymmetry. Our results show that a PGE-driven ${\mathrm{CrI}}_{3}$ photodetector is a promising candidate for low-power 2D spintronic devices.