MSc Thesis Defence - Rafeh Rehan

Optical Signatures of Topological Phases in the Gapped α — T3 Model

MSc Candidate - Rafeh Rehan

Abstract

We investigate the optical signatures of topological phases in the α — T3 model, considering a non-zero staggered lattice magnetization (SLM) and intrinsic spin-orbit coupling (ISOC) of the Kane-Mele type. First, we review the graphene, honeycomb, and dice lattice configurations under these effects, and their finite frequency responses. We then introduce the α — T3 model as an interpolation between graphene and the dice lattice. We utilize band touching events at low energies to confirm previously identified topological phase transitions in literature. We use this
connection to explore and categorize unique valley-and spin-dependent optical signatures, sensitive to the value of the chemical potential, for each topological phase in the low-energy gapped α — T3 model.

Examination Committee

• Dr. Robert Wickham, Chair
• Dr. Elisabeth Nicol, Advisor
• Dr. Michael Massa, Advisory Committee
• Dr. De-Tong Jiang, Advisory Committee