Breaking the symmetry of spin-sublattices in antiferromagnet by interfacial tailoring in the L1(0)-MnPt/NaCl/Fe junction

The detection of magnetization states of the antiferromagnets is a precondition to read the binary bits (0 and 1) for the magnetic recording. The magnetoresistance effect has been utilized to detect the magnetization states in commercially ferromagnetic spintronic devices. However, reading the magnetization states of antiferromagnets is extremely hard because of the absence of net magnetic moment in the antiferromagnetic materials. Here, to generate the tunneling magnetoresistance effect in an antiferromagnetic device with the compensated surface, a method of interlayer selection and interfacial tailoring was proposed to break the symmetry of spin-sublattices in antiferromagnets. The stacking structure of the device is L1(0)-MnPt/NaCl/Fe. The C-type antiferromagnet L1(0)-MnPt was used as the antiferromagnetic electrode, and Fe was the other electrode. NaCl was selected as the barrier layer to break the symmetry of spin-sublattices in L1(0)-MnPt by considering the lattice constants of different materials. It is confirmed that the device with the Mn terminal shows the C-4v symmetry in which the spin-sublattices symmetry of L1(0)-MnPt was broken. As a result, the tunneling magnetoresistance ratio of the present device can be up to 200%, which is much larger than the reported ratios of both anisotropic magnetoresistance and the spin Hall magnetoresistance effect in the antiferromagnetic devices, showing a great potential application to read the magnetization states of the antiferromagnetic devices. The spin-dependent transport mechanism of the present device was analyzed in detail by the k-resolved transmission and the local density of states. This study would be beneficial to promote the development of antiferromagnetic spintronics.