Magnetic quantum tunnelling in Fe8 with excited nuclei

Abstract

We investigate the effect of dynamic nuclear spin fluctuation on quantum tunneling of the magnetization (QTM) in the molecular magnet Fe8 by increasing the nuclei temperature using radio frequency (RF) pulses before the hysteresis loop measurements. The RF pulses do not change the electrons spin temperature. Independently we show that the nuclear spin-spin relaxation time T2 has strong temperature dependence. Nevertheless, we found no effect of the nuclear spin temperature on the tunneling probability. This suggests that in our experimental conditions only the hyperfine field strength is relevant for QTM. We demonstrate theoretically how this can occur.

4 pages, 4 figures

References in corpus (6)

• The effects of nuclear spins on the quantum relaxation of the magnetization for the molecular nanomagnet Fe_8
• Nonadiabatic Landau Zener tunneling in Fe_8 molecular nanomagnets
• Landau Zener method to study quantum phase interference of Fe8 molecular nanomagnets
• Proton Spin Relaxation Induced by Quantum Tunneling in Fe8 Molecular Nanomagnet
• Dynamics and thermalization of the nuclear spin bath in the single-molecule magnet Mn12-ac: test for the theory of spin tunneling
• Electromagnetic radiation emanating from the molecular nanomagnet Fe8