Tunneling Rate for Superparamagnetic Particles by the Instanton Method
arXiv:cond-mat/0207744 · doi:10.1016/S0378-4371(02)00620-9
Abstract
We derive the tunneling rate for paramagnetic molecules in the context of a collective spin model. By means of path integral methods an analytical expression is derived. Given the very large spins in question (s ~ 3000 hbar), the observation of magnetization changes due to pure unitary tunnel effects is unlikely.
16 pages, 2 figures