Artificial magnetic field induced by an evanescent wave

TL;DR

This paper demonstrates how an evanescent wave can create artificial magnetic fields in cold atomic gases, leading to observable phenomena like vortices in Bose-Einstein condensates and reflection of falling atoms, advancing quantum simulation techniques.

Contribution

It introduces a method to generate strong artificial magnetic fields using evanescent waves, enabling new quantum simulation experiments with neutral atoms.

Findings

Artificial magnetic fields induce vortices in Bose-Einstein condensates.

Evanescent wave fields can reflect falling atomic clouds.

The method allows measurable effects in cold atomic gases.

Abstract

Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabatic motion of atoms in the presence of an evanescent wave. Theoretical description of the adiabatic motion involves artificial vector and scalar potentials related to the Berry phases. Due to the large gradient of the evanescent field amplitude, the potentials can be strong enough to induce measurable effects in cold atomic gases. We show that the resulting artificial magnetic field is able to induce vortices in a Bose-Einstein condensate trapped close to a surface of a prism where the evanescent wave is created. We also analyze motion of an atomic cloud released from a magneto-optical trap that falls down on the surface of the prism. The artificial magnetic field is able to reflect falling atoms that can be observed experimentally.