Switchable altermagnetism and Luttinger-compensated ferrimagnetism in graphene-MnPS3 heterostructures

Altermagnetism (AM) and Luttinger-compensated ferrimagnetism (LC-FiM) both combine zero net magnetization with spin-split electronic bands, but realizing both states and their interconversion within a single platform remains a significant challenge. Using first-principles calculations and symmetry analysis, we show that a graphene-MnPS 3 van der Waals (vdW) heterostructure provides exactly such a platform. The graphene layer breaks the \({{\mathcal{P}}}{{\mathcal{T}}}\) symmetry of Néel-antiferromagnetic MnPS 3 , and the interfacial stacking dictates the symmetry relation between the two spin sublattices: hollow stacking preserves joint rotation and mirror operations, yielding an i -wave AM state with momentum-dependent spin splitting, while top stacking removes all sublattice-connecting symmetries and stabilizes an LC-FiM state with globally spin-split bands. The two phases are separated by an ultralow sliding barrier of 28 meV/f.u., allowing reversible switching by interlayer translation alone. Out-of-plane (OOP) pressure further amplifies the exchange spin splitting to 72.2 meV (AM) and 80.2 meV (LC-FiM), arising from strengthened interfacial coupling accompanied by enhanced orbital hybridization and asymmetric built-in polarization. Beyond the ideal-stacking limit, the intrinsic lattice mismatch generates a moiré superlattice of alternating AM and LC-FiM domains with distinct magneto-optical Kerr signatures. These results establish interfacial symmetry engineering as a general route to programmable compensated magnetism in vdW materials.