Single Molecule Magnetoresistance with Combined Antiferromagnetic and Ferromagnetic Electrodes

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

<i>GW</i>100: Benchmarking <i>G</i>₀<i>W</i>₀ for Molecular Systems

We present the <i>GW</i>100 set. <i>GW</i>100 is a benchmark set of the ionization potentials and electron affinities of 100 molecules computed with the <i>GW</i> method using three independent <i>GW</i> codes and different <i>GW</i> methodologies. The quasi-particle energies of the highest-occupied molecular orbitals (HOMO) and lowest-unoccupied molecular orbitals (LUMO) are calculated for the <i>GW</i>100 set at the <i>G</i>₀<i>W</i>₀@PBE level using the software packages TURBOMOLE, FHI-aims, and Berkeley<i>GW</i>. The use of these three codes allows for a quantitative comparison of the type of basis set (plane wave or local orbital) and handling of unoccupied states, the treatment of core and valence electrons (all electron or pseudopotentials), the treatment of the frequency dependence of the self-energy (full frequency or more approximate plasmon-pole models), and the algorithm for solving the quasi-particle equation. Primary results include reference values for future benchmarks, best practices for convergence within a particular approach, and average error bars for the most common approximations