Adiabatic Spin Pump through a Molecular Antiferromagnet Ce3Mn8III

Abstract

We show that the spin-dependent charging energy recently discovered in a molecular antiferromagnet enables an adiabatic spin pump, without requiring a magnetic field or tunable spin–orbit coupling, when the molecule is connected to two unpolarized electrodes with oscillating chemical potentials. Onsite Coulomb repulsion between electrons of opposite spin orientations causes a spin-dependent suppression of the current between the two leads, leading to a pumped spin current. Consequently, the Berry-phase-like geometric current is highly spin-polarized. We explore the space of driving parameters to demonstrate the generation of either a fully polarized or a pure spin current. Negative differential conductance is also predicted. These possibilities highlight the advantage of molecular antiferromagnets over ferromagnetic molecules and quantum dots in generating and manipulating low-power spin currents.