TY - JOUR
T1 - The Kronig-Penney model in a quadratic channel with δ interactions
T2 - II. Scattering approach
AU - Smilansky, null
N1 - Funding Information:
This work was concluded in the University of Bath, where the author was nominated a David Parkin visiting professor in the department of mathematical studies. Thanks for the kind hospitality are very much due. This work started as a collaboration with Professor Italo Guarneri, and his ideas and critical comments where essential throughout. Thanks Italo! Thanks are also due to my two old time colleagues and friends—Professor Sven Gnutzmann who accompanied this project with a study of multi-mode quantum graphs and offered invaluable suggestions, and Professor Gregory Berkolaiko for pointing out several errors which existed in the previous version of the manuscript.
PY - 2022/10/28
Y1 - 2022/10/28
N2 - The main purpose of the present paper is to introduce a scattering approach to the study of the Kronig-Penney model in a quadratic channel with δ interactions, which was discussed in full generality in the first paper of the present series. In particular, a secular equation whose zeros determine the spectrum will be written in terms of the scattering matrix from a single δ. The advantages of this approach will be demonstrated in addressing the domain with total energy E ∈ [ 0 , 1 2 ) , namely, the energy interval where, for under critical interaction strength, a discrete spectrum is known to exist for the single δ case. Extending this to the study of the periodic case reveals quite surprising behavior of the Floquet spectra and the corresponding spectral bands. The computation of these bands can be carried out numerically, and the main features can be qualitatively explained in terms of a semi-classical framework which is developed for the purpose.
AB - The main purpose of the present paper is to introduce a scattering approach to the study of the Kronig-Penney model in a quadratic channel with δ interactions, which was discussed in full generality in the first paper of the present series. In particular, a secular equation whose zeros determine the spectrum will be written in terms of the scattering matrix from a single δ. The advantages of this approach will be demonstrated in addressing the domain with total energy E ∈ [ 0 , 1 2 ) , namely, the energy interval where, for under critical interaction strength, a discrete spectrum is known to exist for the single δ case. Extending this to the study of the periodic case reveals quite surprising behavior of the Floquet spectra and the corresponding spectral bands. The computation of these bands can be carried out numerically, and the main features can be qualitatively explained in terms of a semi-classical framework which is developed for the purpose.
KW - Floquet spectrum
KW - Kronig-Penney model
KW - multimode graph
KW - quantum graphs
UR - http://www.scopus.com/inward/record.url?scp=85141987983&partnerID=8YFLogxK
U2 - 10.1088/1751-8121/ac9357
DO - 10.1088/1751-8121/ac9357
M3 - Article
AN - SCOPUS:85141987983
VL - 55
JO - Journal of Physics A: Mathematical and Theoretical
JF - Journal of Physics A: Mathematical and Theoretical
SN - 1751-8113
IS - 42
M1 - 424007
ER -