2024/07/19 by Ulashov, Sobir, Khamidov, Shakhobiddin, Lakaev, Shukhrat
#FOS: Physical sciences #Mathematical Physics (math-ph)
paper · doi:10.48550/arxiv.2407.14033
We study the Schrödinger operators Hλμ(K) with K∈\mathbbT2 being the fixed quasimomentum of a pair of particles, associated with a system of two arbitrary particles on a two-dimensional lattice ℤ2 with on-site and nearest-neighbor interactions of strengths λ∈ℝ and μ∈ℝ, respectively. We divide the (λ,μ)-plane of parameters λ and μ into connected components, such that in each component, the Schrödinger operator Hλμ(0) has a fixed number of eigenvalues. These eigenvalues are located both below the bottom of the essential spectrum and above its top. Additionally, we establish a sharp lower bound for the number of isolated eigenvalues of Hλμ(K) within each connected component.