Topological phases in interacting spin-1 systems

Abstract

The transitions among different topological phases of quantum systems has become a focus area in recent decades. In particular, the question of how to realize and manipulate systems with nontrivial first Chern number is pursued both experimentally and theoretically. Here we go beyond typical spin 1/2 systems and consider both single and coupled spin 1 systems as a means of realizing higher first Chern numbers and studying the transitions between different topological phases. We show that rich topological phase diagrams can be realized by coupling two spin 1 systems using both numerical and analytical methods. Furthermore, we consider a concrete realization of spin 1 systems using superconducting circuits. This realization includes non-standard spin-spin interaction terms that may endanger the topological properties. However, as we argue here, the realistic circuit Hamiltonian including all terms should be expected to show the rich phase structure as well. This puts our predictions within reach of state-of-the-art experimental setups.