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arXiv 1608.04032math-phmath.MP
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多重Dirac δ势的一维半相对论哈密顿量

One-Dimensional Semirelativistic Hamiltonian with Multiple Dirac Delta Potentials

Fatih Erman, Manuel Gadella, Haydar Uncu

摘要:

本文考虑粒子与$N$ Dirac δ势相互作用的一维半相对论薛定谔方程。利用热核技术,我们建立了一个预解式的$N \times N$矩阵,称为主矩阵。这个矩阵基本上包含了关于问题的所有信息。我们通过计算主矩阵的本征值来研究束缚态谱。借助Feynman-Hellmann定理,我们分析了束缚态能量随模型参数的变化。我们还证明了至多存在$N$束缚态,并明确地导出了束缚态的波函数。特别研究了双中心情形的束缚态问题。我们证明了该系统的基态能量是有界的,并且存在一个与预解式相关的自伴哈密顿量。此外,我们还证明了该体系的基态是非简并的。通过精确求解半相对论Lippmann-Schwinger方程,分析了$N$中心的散射问题。反射和透射系数的数值和渐近计算的两个中心的情况下。我们观察到所谓的阈值异常的两个对称定位的中心。半相对论版本的Kronig-Penney模型进行了简短的讨论,并说明了光谱的带隙结构。讨论了无质量情况下的束缚态和散射问题。最后,我们求解了重整化群方程组,非微扰地计算了β函数。

英文摘要:

In this paper, we consider the one-dimensional semirelativistic Schrödinger equation for a particle interacting with $N$ Dirac delta potentials. Using the heat kernel techniques, we establish a resolvent formula in terms of an $N \times N$ matrix, called the principal matrix. This matrix essentially includes all the information about the spectrum of the problem. We study the bound state spectrum by working out the eigenvalues of the principal matrix. With the help of the Feynman-Hellmann theorem, we analyze how the bound state energies change with respect to the parameters in the model. We also prove that there are at most $N$ bound states and explicitly derive the bound state wave function. The bound state problem for the two-center case is particularly investigated. We show that the ground state energy is bounded below, and there exists a self-adjoint Hamiltonian associated with the resolvent formula. Moreover, we prove that the ground state is nondegenerate. The scattering problem for $N$ centers is analyzed by exactly solving the semirelativistic Lippmann-Schwinger equation. The reflection and the transmission coefficients are numerically and asymptotically computed for the two-center case. We observe the so-called threshold anomaly for two symmetrically located centers. The semirelativistic version of the Kronig-Penney model is shortly discussed, and the band gap structure of the spectrum is illustrated. The bound state and scattering problems in the massless case are also discussed. Furthermore, the reflection and the transmission coefficients for the two delta potentials in this particular case are analytically found. Finally, we solve the renormalization group equations and compute the beta function nonperturbatively.

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。

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