Edge states in 2D lattices with hopping anisotropy and Chebyshev polynomials

Autor: Eliashvili, M., Japaridze, G. I., Tsitsishvili, G., Tukhashvili, G.
Rok vydání: 2014
Předmět:
Zdroj: J. Phys. Soc. Jpn., 83 (2014) 044706
Druh dokumentu: Working Paper
DOI: 10.7566/JPSJ.83.044706
Popis: Analytic technique based on Chebyshev polynomials is developed for studying two-dimensional lattice ribbons with hopping anisotropy. In particular, the tight-binding models on square and triangle lattice ribbons are investigated with anisotropic nearest neighbouring hoppings. For special values of hopping parameters the square lattice becomes topologically equivalent to a honeycomb one either with zigzag or armchair edges. In those cases as well as for triangle lattices we perform the exact analytic diagonalization of tight-binding Hamiltonians in terms of Chebyshev polynomials. Deep inside the edge state subband the wave functions exhibit exponential spatial damping which turns into power-law damping at edge-bulk transition point. It is shown that strong hopping anisotropy crashes down edge states, and the corresponding critical conditions are found.
Comment: 10 pages, misprints in formulae (65) corrected
Databáze: arXiv