Wannier-Stark states in double-periodic lattices. I. One-dimensional lattices
Wannier-Stark states in double-periodic lattices. I. One-dimensional lattices
We analyze the Wannier-Stark spectrum of a quantum particle in generic one-dimensional double-periodic lattices. In the limit of a weak static field, the spectrum is shown to be a superposition of two Wannier-Stark ladders originating from two Bloch subbands. As the strength of the field is increased, the spectrum rearranges …