The fractional angular momentum realized by a cold neutral atom

TL;DR

This paper proposes a method to realize fractional angular momentum in a cold neutral atom with a magnetic dipole, interacting with electric fields and trapped harmonically, revealing fractional eigenvalues at low kinetic energy levels.

Contribution

It introduces a novel approach to generate fractional angular momentum in neutral atoms based on electromagnetic duality and compares it with an alternative method.

Findings

Eigenvalues of angular momentum can be fractional at low energy levels.

The fractional angular momentum is dual to that in charged particle systems.

Two different methods to achieve fractional angular momentum are analyzed.

Abstract

Inspired by the electromagnetic duality, we propose an approach to realize the fractional angular momentum by using a cold atom which possesses a permanent magnetic dipole momentum. This atom interacts with two electric fields and is trapped by a harmonic potential which enable the motion of the atom to be planar and rotationally symmetric. We show that eigenvalues of the canonical angular momentum of the cold atom can take fractional values when the atom is cooled down to its lowest kinetic energy level. The fractional part of canonical angular momentum is dual to that of the fractional angular momenta realized by using a charged particle. Another approach of getting the fractional angular momentum is also presented. The differences between these two approaches are investigated.