Fig. 6
From: Double-Gated Nanohelix as a Novel Tunable Binary Superlattice
Square of the dimensionless momentum operator matrix element between the gth and fth subbands in the first Brillouin zone as a function of the dimensionless wave vector q of the electrons photoexcited by right-handed circularly polarized radiation |Tx+iTy|2 and for a variety of parameter combinations spanning the first incident of resonance. a The blue curves denote transitions between the ground and first band while the red curves denote transitions between the ground and second band, both with the following parameters: Ag=0.5 and Bg=0.3 for solid curves, Ag=0.5 and Bg=0.1 for dashed curves, Ag=0.3 and Bg=0.3 for dot-dashed curves, and Ag=0.01 and Bg=0.3 for dotted curves (as Ag→0 the maximum of the 0→2 increases rapidly as it approaches q=− 1/2). The inset plots the behaviour as Bg is tuned through resonance for Ag=0.5; dotted is Bg=0.24, dot-dashed is Bg=0.25, and dashed is Bg=0.26. The solid purple (orange) curve denotes transitions between the ground and first (second) band at resonance with C⊥=0.05 applied. b Plots transitions between the first and second bands. The different blue curves keep Ag=0.5 fixed and vary Bg=0, 0.2, and 0.3 corresponding to dotted, dot-dashed, and solid. The different red curves keep Bg=0.3 fixed while varying Ag=0.05, 0.1, and 0.3 as dotted, dot-dashed, and solid. We have omitted plots for C⊥≠0 here as it yields no great qualitative change to the matrix elements