Dispersion relations of strained and complex lieb lattices based on the tight-binding method

We investigate dispersion relations of strained complex Lieb lattices systematically, based on the tight-binding method with the nearest-neighbor approximation adopted. We find that there are edge states for strained Lieb lattices with solid edges, while there are no edge states for the pointy and pointy-solid edges. Different from honeycomb lattices, the PT -symmetric Lieb lattices cannot be generated.