玻色- Hubbard 奇点的幺正展开：有无粒子数守恒的情况
Unitary unfoldings of Bose-Hubbard exceptional point with and without particle number conservation
AI总结：
研究了具有和不具有粒子数守恒的玻色-哈伯德系统在奇点极限下的幺正展开，揭示了扰动结构的反直觉特性。
摘要：
非厄运但具有PT对称性的N重玻色系统，由三个参数的玻色-哈伯德哈密顿量H(γ,v,c)描述，在其特殊奇点极限c→0和γ→v时，作为广义玻色-哈伯德类哈密顿量家族H(λ)=H(v,v,0)+λV的未扰部分被选取。这导致了两种不同的哈密顿量家族H(λ)的构造。在第一种情况下假设玻色子数目N被守恒，而在第二种情况下则放松了这一假设。在两种情况下都显示了相关物理希尔伯特空间的各向异性，通过高度反直觉但可操作实现的允许扰动λV的结构得以反映。
英文摘要：
Non-Hermitian but ${\cal PT}-$symmetric quantum system of an $N-$plet of bosons described by the three-parametric Bose-Hubbard Hamiltonian $H(γ,v,c)$ is picked up, in its special exceptional-point limit $c \to 0$ and $γ\to v$, as an unperturbed part of the family of generalized Bose-Hubbard-like Hamiltonians $\mathfrak{H}(λ)=H(v,v,0)+λ\,{\cal V}$ for which the unitarity of the perturbed system is required. This leads to the construction of two different families of Hamiltonians $\mathfrak{H}(λ)$. In the first one the number $N$ of bosons is assumed conserved while in the second family such an assumption is relaxed. In both cases the anisotropy of the related physical Hilbert space is shown reflected by a highly counterintuitive but operationally realizable structure of admissible perturbations $λ\,{\cal V}$.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
