Experimental Upper Bound on Superradiance Emission from Mn12 Acetate

Abstract

We used a Josephson junction as a radiation detector to look for evidence of the emission of electromagnetic radiation during magnetization avalanches in a crystal assembly of Mn_12-Acetate. The crystal assembly exhibits avalanches at several magnetic fields in the temperature range from 1.8 to 2.6 K with durations of the order of 1 ms. Although a recent study shows evidence of electromagnetic radiation bursts during these avalanches [J. Tejada, et al., Appl. Phys. Lett. {\bf 84}, 2373 (2004)], we were unable to detect any significant radiation at well-defined frequencies. A control experiment with external radiation pulses allows us to determine that the energy released as radiation during an avalanche is less than 1 part in 10^4 of the total energy released. In addition, our avalanche data indicates that the magnetization reversal process does not occur uniformly throughout the sample.

4 RevTeX pages, 3 eps figures

References in corpus (11)

• Quantum Computing in Molecular Magnets
• The origin of second-order transverse magnetic anisotropy in Mn12-acetate
• Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12
• Definitive spectroscopic determination of the transverse interactions responsible for the magnetic quantum tunneling in Mn12-acetate
• Spin tunneling via dislocations in Mn-12 acetate crystals
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• Superradiance from crystals of molecular nanomagnets
• A Distribution of Tunnel Splittings in Mn${}_{12}$-Acetate
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Cited by in corpus (10)

• Resonant Tunneling in Truly Axial Symmetry Mn12 Single-Molecule Magnets: Sharp Crossover between Thermally Assisted and Pure Quantum Tunneling
• Propagation of Avalanches in Mn${}_{12}$-acetate: Magnetic Deflagration
• Coherent spin relaxation in molecular magnets
• Microwave emission from a crystal of molecular magnets -- The role of a resonant cavity
• Intrinsic avalanches and collective phenomena in a Mn(II)-free radical ferrimagnetic chain
• Coherent radiation by molecular magnets
• Field-dependent superradiant quantum phase transition of molecular magnets in microwave cavities
• Electromagnetic radiation emanating from the molecular nanomagnet Fe8
• Influence of thermal coupling on spin avalanches in Mn12-acetate
• Energy emanating from the molecular nanomagnet Fe${}_8$ revisited