We consider the quasi Hermitian limit of a non-Hermitian extended Su
Schrieffer Heeger model, in which the hopping amplitudes obey a specific
relation so that the system may be mapped to a corresponding Hermitian one and
its energy spectrum is completely real. Analogous to the Hermitian case, one
may use the modified winding number to determine the total number of edge
states on the boundaries to achieve a modified bulk-boundary correspondence.
Due to the skin effect in nonHermitian systems, the spectral winding numbers
must be used to classify such systems further. It dictates how the edge states
would be distributed over the left and right boundaries. We then naively extend
the criteria to the cases that the quasi Hermitian condition is violated. For
all the cases that we consider, no inconsistency has been found.Comment: 21 pages, 10 figure