Quantum simulation of ferromagnetic and anti-ferromagnetic tunneling anisotropic magnetoresistance in a single-molecule-magnet dimer tunnel-junction

In this work, we simulate the tunneling anisotropic magnetoresistance (TAMR) in a single-molecule-magnet (SMM) dimer tunnel-junction with metal and ferromagnetic (FM) electrodes. The non-collinear polarization of electrode with respect to the uniaxial anisotropy-axis of magnet results in both the FM and anti-ferromagnetic (AFM) TAMR respectively for the FM and AFM inter-molecule couplings. In terms of the spin coherent state representation of electron spin the non-collinear tunneling is able to be analyzed with the usual rate equation approach in a sequential tunneling regime. The ferromagnetic TAMR varies with the non-collinear angle and the tunneling magnetoresistance (TMR) is just a special case of the angle θ = π. With the FM dimer we obtain the higher TMR up to 400% and the high polarization rate (79%) of spin current as well. The angle dependence of TAMR for the AFM dimer is also presented along with the spin current.In this work, we simulate the tunneling anisotropic magnetoresistance (TAMR) in a single-molecule-magnet (SMM) dimer tunnel-junction with metal and ferromagnetic (FM) electrodes. The non-collinear polarization of electrode with respect to the uniaxial anisotropy-axis of magnet results in both the FM and anti-ferromagnetic (AFM) TAMR respectively for the FM and AFM inter-molecule couplings. In terms of the spin coherent state representation of electron spin the non-collinear tunneling is able to be analyzed with the usual rate equation approach in a sequential tunneling regime. The ferromagnetic TAMR varies with the non-collinear angle and the tunneling magnetoresistance (TMR) is just a special case of the angle θ = π. With the FM dimer we obtain the higher TMR up to 400% and the high polarization rate (79%) of spin current as well. The angle dependence of TAMR for the AFM dimer is also presented along with the spin current.