Composite symmetry protected topological order and effective models

Understand

Strongly correlated quantum many-body systems at low dimension exhibit a wealth of phenomena, ranging from features of geometric frustration to signatures of symmetry-protected topological order.

• In suitable descriptions of such systems, it can be helpful to resort to effective models which focus on the essential degrees of freedom of the given model.
• In this work, we analyze how to determine the validity of an effective model by demanding it to be in the same phase as the original model.
• We focus our study on one-dimensional spin-1/2 systems and explain how non-trivial symmetry protected topologically ordered (SPT) phases of an effective spin 1 model can arise depending on the couplings in the original Hamiltonian.