# Topological bound states for quantum charges

## TL;DR

This paper explores how semifluxon-carrying solenoids can create topological energy barriers in quantum systems through the Aharonov-Bohm effect, leading to bound states and nodal lines in the wave function.

## Contribution

It introduces a novel method of using solenoids as topological barriers for quantum charges, highlighting their role in inducing wave function nodal lines and bound states.

## Key findings

- Solenoids with semifluxons act as topological energy barriers.
- Nodal lines in wave functions result from the Aharonov-Bohm effect.
- Two solenoids can create bound states in a cavity.

## Abstract

We discuss how, in appropriately designed configurations, solenoids carrying a semifluxon can be used as topological energy barriers for charged quantum systems. We interpret this phenomenon as a consequence of the fact that such solenoids induce nodal lines in the wave function describing the charge, which on itself is a consequence of the Aharonov-Bohm effect. Moreover, we present a thought experiment with a cavity where two solenoids are sufficient to create bound states.