Symmetry of Magnetic Quantum Tunneling in Single Molecule Magnet Mn12-acetate

Abstract

The symmetry of magnetic quantum tunneling has been studied in the prototype single molecule magnet Mn${}_{12}$-acetate using a micro-Hall effect magnetometer and superconducting high field vector magnet system. An average crystal fourfold symmetry is shown to be due to local molecular environments of twofold symmetry that are rotated by 90${}^o$ with respect to one another, confirming that disorder which lowers the molecule symmetry is at important to magnetic quantum tunneling. We have studied a subset of these lower (twofold) site symmetry molecules and present evidence for a Berry phase effect consistent with a local twofold symmetry.

4 pages and 3 figures

References in corpus (14)

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• Manipulating the Quantum State of an Electrical Circuit
• High frequency EPR spectra of a molecular nanomagnet provide a key to understand Quantum Tunneling of the Magnetization
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• The origin of second-order transverse magnetic anisotropy in Mn12-acetate
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• Definitive spectroscopic determination of the transverse interactions responsible for the magnetic quantum tunneling in Mn12-acetate
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• Quantum Coherence in Fe8 Molecular Nanomagnets
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• Tunneling Splittings in Mn12-Acetate Single Crystals
• Crystal defects and spin tunneling in single crystals of Mn12 clusters

Cited by in corpus (37)

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• Evidence for the S=9 excited state in Mn12-bromoacetate measured by electron paramagnetic resonance
• Transverse Magnetic Anisotropy in Mn12-acetate: Direct Determination by Inelastic Neutron Scattering
• Crystal lattice desolvation effects on the magnetic quantum tunneling of single-molecule magnets
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• Asymmetric Berry-Phase Interference Patterns in a Single-Molecule Magnet
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• Experimental Upper Bound on Superradiance Emission from Mn12 Acetate
• Observation of a Distribution of Internal Transverse Magnetic Fields in a Mn12-Based Single Molecule Magnet
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• How systems of single-molecule magnets magnetize at low temperatures
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• Collective electromagnetic relaxation in crystals of molecular magnets
• Turbulent fronts of quantum detonation in molecular magnets
• Effects of uniaxial pressure on the quantum tunneling of magnetization in a high-symmetry Mn12 single-molecule magnet
• Incommensurate Transverse Anisotropy Induced by Disorder and Spin-Orbit-Vibron Coupling in Mn12-acetate
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• On-chip Integration of High-Frequency Electron Paramagnetic Resonance Spectroscopy and Hall-Effect Magnetometry
• Transverse Field Ising Ferromagnetism in Mn${}_{12}$-acetate-MeOH
• Entrapment of magnetic micro-crystals for on-chip electron spin resonance studies
• The effect of uniaxial pressure on the magnetic anisotropy of the Mn_{12}-Ac single-molecule magnet
• Quantum Fluctuations and Long-Range Order in Molecular Magnets