Molecular Magnetism

Spin transistors

Bulk samples and surface monolayers of magnetic molecules have been investigated extensively. They show a variety of unique properties, such as spin-state tunability by light irradiation, magnetic hysteresis and quantum tunneling of the magnetization. Studies on the single-molecule level, however, are scarce. As a consequence, the key questions for exploiting their unique properties in device configurations have remained largely unanswered: “How can spins be manipulated at the molecular nanoscale?” and “Does a single molecule connected to metal electrodes retain its magnetic properties?”

We fabricate planar three-terminal nanodevices containing individual magnetic molecules or nanoparticles. Instead of being introduced by the electrodes, the magnetic functionality is placed in between the source and drain electrodes, which are made of noble metals or of (multi-layered) graphene. In this way a spin transistor is built in which the electric current through the individual magnetic molecule or nanoparticle is sensitive to its spin properties. The molecular complexes of interest are single-molecule magnets, and spin-crossover compounds.

Electron transport through single Mn12 molecular nanomagnets
H.B. Heersche et al., Phys. Rev. Lett. 96 (2006) 206801 (arXiv:cond-mat/0510732)

Electrical manipulation of spin states in a single gated transition-metal complex
E.A. Osorio et al., Nano Letters 10 (2010) 105-110

Electric field-controlled magnetic anisotropy in a single molecule
A. Zyazin et al., Nano Letters 10 (2010) 3307-3311

Electric control over the Fe(II) spin transition in a single molecule: Theory and experiment
V. Meded et al., Phys. Rev. B 83 (2011) 245115

High-spin and magnetic anisotropy signatures in three-terminal transport through a single molecule
A. Zyazin, H.S.J. van der Zant, M.R. Wegewijs and A. Cornia, Synthetic Metals 161 (2011) 591-597

Direct observation of magnetic anisotropy in an individual Fe4 single-molecule magnet
E. Burzuri et al., Phys. Rev. Lett. 109 (2012) 147203