Spectral Transition for Dirac Operators with Electrostatic δ -Shell Potentials Supported on the Straight Line

Integr Equ Oper Theory. 2022;94(3):33. doi: 10.1007/s00020-022-02711-6. Epub 2022 Aug 30.

Abstract

In this note the two dimensional Dirac operator A η with an electrostatic δ -shell interaction of strength η R supported on a straight line is studied. We observe a spectral transition in the sense that for the critical interaction strengths η = ± 2 the continuous spectrum of A η inside the spectral gap of the free Dirac operator A 0 collapses abruptly to a single point.

Keywords: Boundary triple; Dirac operator; Singular potential; Spectral transition.