The magnetoresistance of a hydrogen-phthalocyanine molecule placed on an antiferromagnetic Mn(001) surface and contacted by a ferromagnetic Fe electrode is investigated using density functional theory based transport calculations and low-temperature scanning tunneling microscopy. A large and negative magnetoresistance ratio of 50% is observed in combination with a high conductance. The effect originates from a lowest unoccupied molecular orbital (LUMO) doublet placed almost in resonance with the Fermi energy. As a consequence, irrespective of the mutual alignment of magnetizations, electron transport is always dominated by resonant transmission of Mn-majority charge carries going through LUMO levels.
Single molecule magnetoresistance with combined antiferromagnetic and ferromagnetic electrodes
Alexei Bagrets, Stefan Schmaus, Ali Jaafar, Detlef Kramczynski, Toyo Kazu Yamada, Mebarek Alouani, Wulf Wulfhekel and Ferdinand Evers