Plasmonic surface traps with arbitrary shape for cold atoms

TL;DR

This paper explores the design and experimental realization of plasmonic surface traps with arbitrary shapes for cold atoms, utilizing locally tunable evanescent fields generated by nanostructured metal layers.

Contribution

It introduces a method to create customizable potential landscapes for cold atoms using plasmonic enhancements and demonstrates initial experimental validation.

Findings

Simulations of a plasmonic lattice potential with a gold grating.

Experimental characterization of a plasmonic test structure.

Detection of surface potential landscape via ultracold atom reflection.

Abstract

This paper reports on conceptual and experimental work towards the realization of plasmonic surface traps for cold atoms. The trapping mechanism is based on the combination of a repulsive and an attractive potential generated by evanescent light waves that are plasmonically enhanced. The strength of enhancement can be locally manipulated via the thickness of a metal nanolayer deposited on top of a dielectric substrate. Thus, in principle arbitrary potential landscapes can be generated. We present simulations of a plasmonic lattice potential using a gold grating with sinusoidally modulated thickness. Experimentally, a first plasmonic test structure is presented and characterized. Furthermore, the surface potential landscape is detected by reflecting ultracold atom clouds from the test structure revealing the influence of both evanescent waves. A parameter range is identified, where stable traps can be expected.