Moiré-like Superlattice Generated van Hove Singularities in a Strained CuO2 Double Layer

While it is known that the double-layer Bi2Sr2CaCu2O8+y (BSCCO) cuprate superconductor exhibits a one-dimensional (1D) incommensurate superlattice (IS), effect of IS on electronic structure remains elusive. Following recent shift interest from an underdoped phase to optimum and overdoped phases in BSCCO by increasing hole doping x, controlled oxygen interstitials concentration y, here we focus multiple splitting density states (DOS) peaks emergence higher order van Hove singularities (VHS) due 1D superlattice. It wave vector q=ϵb (where b reciprocal lattice orthorhombic lattice) misfit strain between different atomic layers range 0.209–0.215 0.209–0.25 Bi2Sr2Ca1−xYxCu2O8+y (BSCYCO). This work reports theoretical calculation complex pattern VHS with large quasi-commensurate supercells ϵ=9/η 36>η>43. The similarity appearing mismatched CuO2 bilayer moiré strained twisted graphene discussed. makes quite promising for constructing quantum devices tuned physical characteristics.