Single Molecule Electronic Transport through Molecular Magnets

• Applicant: Professor Dr. Herbert Schoeller
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2002 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5369165

Electrical and magnetic devices based on single molecules offer exciting perspectives for the further minituarization of electronic devices with a potentially large impact in applications. To date several experiments have shown the possibility to attach individual molecules to leads and to measure the electrical transport. With recent technological improvements in the design of single-molecule magnets (SMM), experiments and devices that combine spin- and molecular electronics become realistic. Transport through SMM offers several unique features that have not been exploited to date: - SMM couple naturally to applied external magnetic fields and may thus function as magnetic sensors, switches or storage devices. - In the limit of weak coupling between electrodes and SMM a strong interaction between transport effects and magnetic structure can lead to interesting physical effects, such as current assisted spin-tunneling, spin fluctuations leading to Kondo effects, magneto-Coulomb-oscillations, and spin-accumulation. - In contrast to organic systems, the molecular orbitals which carry the current and which are responsible for the magnetic properties of the system are spatially confined, i.e. they are less susceptible to the influence of the external electric field. In this investigation we plan to develop microscopic models to calculate the electronic two-terminal transport though a molecular magnet in the presence of an applied magnetic and electric field and to determine the transport characteristics through such a system for weak coupling between electrode and SMM, where strong Coulomb correlations and many-body effects are important.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1137: Molecular Magnetism
• Participating Person: Professor Dr. Wolfgang Wenzel