Gap asymptotics in a weakly bent leaky quantum wire

摘要

The main question studied in this paper concerns the weak-coupling behavior of the geometrically induced bound states of singular Schrodinger operators with an attractive delta interaction supported by a planar, asymptotically straight curve Gamma. We demonstrate that if Gamma is only slightly bent or weakly deformed, then there is a single eigenvalue and the gap between it and the continuum threshold is in the leading order proportional to the fourth power of the bending angle, or the deformation parameter. For comparison, we analyze the behavior of a general geometrical induced eigenvalue in the situation when one of the curve asymptotes is wiggled.