Photo from academic.microsoft.com
Tight-binding model on a finite chain is studied with four-fold alternated hopping parameters t1,2,3,4. Imposing the open boundary conditions, the corresponding recursion is solved analytically with special attention paid to… Click to show full abstract
Tight-binding model on a finite chain is studied with four-fold alternated hopping parameters t1,2,3,4. Imposing the open boundary conditions, the corresponding recursion is solved analytically with special attention paid to the occurrence of edge states. Corresponding results are strongly corroborated by numeric calculations. It is shown that in the system there exist four different edge phases if the number of sites is odd, and eight edges phases if the chain comprises even number of sites. Phases are labelled by σ1 ≡ sgn(t1t3 − t2t4), σ2 ≡ sgn(t1t4 − t2t3), and σ3 ≡ sgn(t1t2 − t3t4). It is shown that σ1,2,3 represent gauge invariant topological indices emerging in the corresponding infinite chains.
Journal Title: Journal of the Physical Society of Japan
Year Published: 2017
Link to full text (if available)
Share on Social Media: Sign Up to like & get
recommendations!