Theory of Deflagration and Fronts of Tunneling in Molecular Magnets

摘要

Decay of metastable states in molecular magnets (MM) leads to energy releasethat results in temperature increase that, in turn, positively affects thedecay rate. This is the mechanism of recently discovered magnetic deflagrationthat is similar to regular chemical burning and can propagate in a form ofburning fronts in long MM crystals. Near spin-tunneling resonances the decayrate is also affected by the dipolar field (self-consistent with the switchingmagnetization) that can block or unblock tunneling. There are non-thermalfronts of tunneling in which the magnetization adjusts in such a way that thesystem is on resonance within the front core, so that the tunneling front canpropagate. In general, both dipolar field and temperature control fronts ofquantum deflagration. The front speed can reach sonic values if a strongtransverse field is applied to boost tunneling.