Extended states in one-dimensional aperiodic lattices with linearly varying patches

We introduce a family of 1D aperiodic tight-binding models with linearly varying patches of A-type sites with on-site energies ${\epsilon }_A=0$ connected by single B-type sites with ${\epsilon }_B=W$. We analytically show such structures have strong spatial correlations. We theoretically find states are extended at resonance levels in the vicinity of $E_M^{\kappa }=-2\cos \frac{\kappa \pi }{M}$ if they are allowed energies, where $M=md$ are the size differences of patches, $d$ is the variation rate of patch sizes, $m\in {\mathcal{N}}_{+}$ and $\kappa =1,2,\cdots ,M-1$. Related delocalization-localization transitions are explored. Numerical evidences are in excellent quantitative agreement with theoretical predictions.