Plasmonically tailored micropotentials for ultracold atoms

Abstract

Plasmonic near-fields can be structured with sub-optical wavelength resolution. This offers promising scenarios for trapping, guiding and manipulating cold atoms in plasmonically tailored dipole potentials, which could enable strong coupling between a single atom and a single plasmonic excitation. Here, we report on the interaction of Bose-Einstein condensates with the optical near-field above plasmonic micro-and submicrometre structures. At these structures, surface plasmon polaritons are excited by a laser in the Kretschmann configuration, giving rise to resonantly enhanced surface plasmons. We introduce a technique to measure the strength of optical near-fields by observing the reflection of cold atoms from the surface. In particular, the dependence of electromagnetic field enhancement on structure size is investigated. Furthermore, we show that the near-field induced potential landscape can be tailored to sub-micrometre dimensions by demonstrating matter-wave diffraction from a grating of plasmonic wires. © 2011 Macmillan Publishers Limited. All rights reserved.