Underlying mechanism for exchange bias in single molecule magnetic junctions

Magnetic proximity has been observed in variety of solid-state magnetic devices but less discussed at the molecular scale. In this study [1], the magnetotransport calculation is carried out using the generalized Landau-Lifshitz-Gilbert (LLG) equation combined with our self-developed  DFT+JunPy calculated spin torque effect [2,3]. Except the current driven spin torque, which is a promising approach for magnetization switch in magnetic random access memory, the equilibrium field-like spin torque also plays a crucial role in the strain-controlled exchange bias with current-controlled magnetic coercivity in single molecule magnetic junctions. The tight-binding model is further employed to clarify the critical role of interfacial spin filter effect arising from the hybridization between linker and Co apex. These multidisciplinary DFT+JunPy+LLG results may provide important and practical implications in dual control of magnetic proximity and magnetization switching in molecular spintronics at low temperature, either by tensile strain or via smaller applied current density in the order of MA/cm².

Refereces

[1] Y. -H. Tang and B. -H. Huang, Phys. Rev. Research, 3, 033264 (2021).

[2] Y. –H. Tang and B. –H. Huang, J. Phys. Chem. C 122, 20500 (2018).

[3] B. -H. Huang et al., AIP Advacnes 11, 015036 (2021).