Abstract
A criterion to determine the existence of zero-energy edge states is discussed for a class of particle-hole symmetric Hamiltonians. A “loop” in a parameter space is assigned for each one-dimensional bulk Hamiltonian, and its topological properties, combined with the chiral symmetry, play an essential role. It provides a unified framework to discuss zero-energy edge modes for several systems such as fully gapped superconductors, two-dimensional -wave superconductors, and graphite ribbons. A variance of the Peierls instability caused by the presence of edges is also discussed.
- Received 11 December 2001
DOI:https://doi.org/10.1103/PhysRevLett.89.077002
©2002 American Physical Society