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

Abstract

In this note the two dimensional Dirac operator $A_{\eta }$ with an electrostatic $\delta$ -shell interaction of strength $\eta \in R$ supported on a straight line is studied. We observe a spectral transition in the sense that for the critical interaction strengths $\eta =\pm 2$ the continuous spectrum of $A_{\eta }$ inside the spectral gap of the free Dirac operator $A_0$ collapses abruptly to a single point.