Quantum avalanche in the Fe${}_8$ Molecular-Magnet

Abstract

We report spatially resolved, time-dependent, magnetization reversal measurements of an Fe${}_8$ single molecular magnet using a microscopic Hall bar array. We found that under some conditions the molecules reverse their spin direction at a resonance field in the form of an avalanche. The avalanche front velocity is of the order of $1$m/sec and is sensitive to field gradients and sweep rates. We also measured the propagation velocity of a heat pulse and found that it is much slower than the avalanche velocity. We therefore conclude that in Fe${}_8$, the avalanche front propagates without thermal assistance.

References in corpus (2)

• Theory of magnetic deflagration
• Energy emanating from the molecular nanomagnet Fe${}_8$ revisited