Single-Molecule Magnet Mn<sub>12</sub> on GaAs-supported Graphene: Gate Field Effects From First Principles
ORAL
Abstract
We study gate field effects on the Mn12O12(COOH)16(H2O)4 | graphene | GaAs heterostructure via first-principles calculations. We find that under moderate doping levels electrons can be added to but not taken from the single-molecule magnet Mn12O12(COOH)16(H2O)4 (Mn12). The magnetic anisotropy energy (MAE) of Mn12 decreases as the electron doping level increases, due to electron transfer from graphene to Mn12 and change in the band alignment between Mn12 and graphene. At an electron doping level of -5.00 × 1013 cm-2, the MAE decreases by about 18% compared with that at zero doping. The band alignment between graphene and GaAs is more sensitive to electron doping than to hole doping since the valence band of GaAs is close to the Fermi level. The GaAs substrate induces a small bandgap in the supported graphene under the zero gate field and a nearly strain-free configuration. Finally, we propose a vertical tunnel junction for probing the gate dependence of MAE via electron transport measurements.
*This work was supported by the Center for Molecular Magnetic Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No.~DESC0019330. Computations were done using the utilities of NERSC and UFRC.
–
Presenters
-
Hai-Ping Cheng
- University of Florida
- Department of Physics, Center for Molecular Magnetic Quantum Materials and Quantum Theory Project, University of Florida
- Department of Physics, University of Florida
- Physics, University of Florida