Theoretical Studies on Quantum Tunneling of Spins in Cluster of Clusters

Abstract

In this work, we consider a cluster, which consists of small clusters with an anisotropy energy and suppose that the Hamiltonian of each cluster in the cluster is represented by the nonlinear sigma model. We apply a single spin model to the model clusters and calculate the time evolution of spin wavepacket. We demonstrate a magnetic field induced tunneling and elucidate its mechanism.

Key Words:

• quantum tunneling of magnetization
• wavepacket dynamics
• cluster of clusters