Effect of electron correlation in Kronig-Penney model

Ajoy Kumar Ghatak, S. Lokanathan

Zhu Ya, Qiang Tian

Based on the continuity of the wave function and its derivative, the wave function in Kronig-Penney model is analysed. We obtain a transfer matrix connecting the amplitudes of the transmitted and reflected wave function through a barrier. Then the wave function in Kronig-Penney model is derived and discussed.

Bruce H. J. McKellar, G. J. Stephenson

We analyze the barrier problem and the Kronig-Penney model for Dirac particles, paying attention to the Klein paradox and the nature of the potential. The ambiguities associated with the \ensuremath{\delta}-function limit are examined and the physically reasonable way to include \ensuremath{\delta}-function potentials in the Dirac-Kronig-Penney problem is identified.

U. Fano

Marta Sroczyńska, Tomasz Wasak, Zbigniew Idziaszek

We generalize the textbook Kronig-Penney model to realistic conditions for a quantum-particle moving in the quasi-one-dimensional (quasi-1D) waveguide, where motion in the transverse direction is confined by a harmonic trapping potential. Along the waveguide, the particle scatters on an infinite array of regularized delta potentials. Our starting point is the Lippmann-Schwinger equation, which for quasi-1D geometry can be solved exactly, based on the analytical formula for the quasi-1D Green's function. We study the properties of eigenenergies as a function of particle quasimomentum, which form band structure, as in standard Kronig-Penney model. We test our model by comparing it to the numerical calculations for an atom scattering on an infinite chain of ions in quasi-1D geometry. The agreement is fairly good and can be further improved by introducing energy-dependent scattering length in the regularized delta potential. The energy spectrum exhibits the presence of multiple overlapping bands resulting from excitations in the transverse direction. At large lattice constants, our model reduces to standard Kronig-Penney result with 1D coupling constant for quasi-1D scattering, exhibiting confinement-induced resonances. In the opposite limit, when lattice constant becomes comparable to harmonic oscillator length of the transverse potential, we calculate the correction to the quasi-1D coupling constant due to the quantum interference between scatterers. Finally, we calculate the effective mass for the lowest band and show that it becomes negative for large and positive scattering lengths.