Bound States in Sharply Bent Waveguides: Analytical and Experimental Approach

TL;DR

This paper investigates bound states in sharply bent waveguides using both experimental microwave measurements and theoretical effective potential models, analyzing the transition from bound to unbound states as the bending angle varies.

Contribution

It introduces an effective potential approach to analyze bound states in bent waveguides and validates predictions through experiments and numerical calculations.

Findings

Bound states exist in sharply bent waveguides.

Transition from bound to unbound states depends on bending angle.

Critical angles for state transition are identified.

Abstract

Quantum wires and electromagnetic waveguides possess common features since their physics is described by the same wave equation. We exploit this analogy to investigate experimentally with microwave waveguides and theoretically with the help of an effective potential approach the occurrence of bound states in sharply bent quantum wires. In particular, we compute the bound states, study the features of the transition from a bound to an unbound state caused by the variation of the bending angle and determine the critical bending angles at which such a transition takes place. The predictions are confirmed by calculations based on a conventional numerical method as well as experimental measurements of the spectra and electric field intensity distributions of electromagnetic waveguides.