Photon-Induced Magnetization Changes in Single-Molecule Magnets

Abstract

Microwave radiation applied to single-molecule magnets can induce large magnetization changes when the radiation is resonant with transitions between spin levels. These changes are interpreted as due to resonant heating of the sample by the microwaves. Pulsed-radiation studies show that the magnetization continues to decrease after the radiation has been turned off with a rate that is consistent with the spin's characteristic relaxation rate. The measured rate increases with pulse duration and microwave power, indicating that greater absorbed radiation energy results in a higher sample temperature. We also performed numerical simulations that qualitatively reproduce many of the experimental results. Our results indicate that experiments aimed at measuring the magnetization dynamics between two levels resonant with the radiation must be done much faster than the >20-microsecond time scales probed in these experiments.

6 RevTeX pages, including 8 eps figures. Revision: Simulations added to paper. Version accepted by J. Appl. Phys. (MMM'05 conference proceedings)

References in corpus (13)

• Quantum Computing in Molecular Magnets
• High frequency EPR spectra of a molecular nanomagnet provide a key to understand Quantum Tunneling of the Magnetization
• Thermally Activated Resonant Magnetization Tunneling in Molecular Magnets: Mn_12Ac and others
• Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12
• Spin relaxation in Mn12-acetate
• Phonon superradiance and phonon laser effect in nanomagnets
• Quantum Coherence between High Spin Superposition States of Single Molecule Magnet Ni${}_4$
• Photon-assisted tunneling in a Fe8 Single-Molecule Magnet
• Resonant photon absorption in the low spin molecule V15
• Photon-Induced Magnetization Reversal in Single-Molecule Magnets
• Resonant photon absorption and hole burning in Cr7Ni antiferromagnetic rings
• Non-equilibrium Magnetization Dynamics in the Fe_8 Single-Molecule Magnet Induced by High-Intensity Microwave Radiation
• Crystal Field -AS_z^2 Does Not Produce One-Phonon Transitions With Delta S_z=+-2 [Comment on EPL 46, 692 (1999) by Leuenberger and Loss]

Cited by in corpus (8)

• Single-molecule Nanomagnets
• Pump-Probe Experiments on the Single-Molecule Magnet Fe8 : Measurement of Excited Level Lifetimes
• Radiation- and Phonon-Bottleneck-Induced Tunneling in the Fe8 Single-Molecule Magnet
• Tuning Magnetic Avalanches in Mn12-ac
• Magnetization relaxation in the single molecule magnet Ni${}_4$ under continuous microwave irradiation
• Energy Level Lifetimes in the Single-Molecule Magnet Fe_8 : Experiments and Simulations
• Electromagnetic radiation emanating from the molecular nanomagnet Fe8
• Nanoscale functionalized superconducting transport channels as photon detectors