Journal of Physics A: Mathematical and Theoretical ( IF 2.0 ) Pub Date : 2021-05-21 , DOI: 10.1088/1751-8121/abfcf4 Saidakhmat N Lakaev 1 , Shokhrukh Yu Kholmatov 2 , Shakhobiddin I Khamidov 1
We study the discrete spectrum of the two-particle Schrdinger operator , , associated to the Bose–Hubbard Hamiltonian of a system of two identical bosons interacting on site and nearest-neighbor sites in the two dimensional lattice with interaction magnitudes and , respectively. We completely describe the spectrum of and establish the optimal lower bound for the number of eigenvalues of outside its essential spectrum for all values of . Namely, we partition the (μ, λ)-plane such that in each connected component of the partition the number of bound states of below or above its essential spectrum cannot be less than the corresponding number of bound states of below or above its essential spectrum.
中文翻译:
具有现场和最近邻相互作用的 Bose-Hubbard 模型:完全可解的情况
我们研究了两粒子薛定谔算子的离散频谱,相关联的玻色-哈巴德哈密顿两个相同的玻色子在二维网格上的网站,最近邻部位相互作用的系统与互动幅度和分别。我们完整地描述了 的频谱,并为 的所有值的基本频谱之外的特征值数量建立了最优下界。也就是说,我们对 ( μ , λ ) 平面进行分区,使得在分区的每个连通分量中,低于或高于其本征谱不能少于低于或高于其本征谱的相应束缚态数。