Perfect lens makes a perfect trap

Plasmonic field-regulating characteristics of alloy-based multilaminar films in 300-800 nm

Based on a petal-like microstructure model of alloy particles we proposed, the field-regulating characteristics of alloy-based metamaterial films in the wavelength range of 300-800 nm are analyzed. It is found that Au/Ag alloy particles can support a broader resonance band with higher averaged resonance intensities than that of pure silver or gold particles, which, named alloy plasmonic effect, proves to be a universal feature of alloy-based plasmonics. Upon optimizing the coupling interaction between the alloy plasmonic effect and absorption saturation effect within alloy-based multilaminar structures, a broadband electromagnetic wave absorber consisting of a Cu/Al alloy-based composites layer and an aluminum base layer is demonstrated. Furthermore, a generalized method is proposed to evaluate the absorption performance of this kind of plasmonic absorber. The achieved alloy-based absorber proves to be nearly non-iridescent and the quality factor AP throughout the range of 300-800 nm remains higher than 0.8 even if the incident angle increases up to 60°.

Microwave Atom Chip Design

We present a toolbox of microstrip building blocks for microwave atom chips geared towards trapped atom interferometry. Transverse trapping potentials based on the AC Zeeman (ACZ) effect can be formed from the combined microwave magnetic near fields of a pair or a triplet of parallel microstrip transmission lines. Axial confinement can be provided by a microwave lattice (standing wave) along the microstrip traces. Microwave fields provide additional parameters for dynamically adjusting ACZ potentials: detuning of the applied frequency to select atomic transitions and local polarization controlled by the relative phase in multiple microwave currents. Multiple ACZ traps and potentials, operating at different frequencies, can be targeted to different spin states simultaneously, thus enabling spin-specific manipulation of atoms and spin-dependent trapped atom interferometry.

All-optical nanotraps for atoms atop flat metamaterial lenses: a theoretical study

We propose a novel setup for optically trapping neutral atoms based upon the focusing properties of metamaterials. The optical trap is created at the focal point of an inverted-opal crystal when the latter is illuminated by a localized light source. The trap is located away from the surface of the inverted-opal lens, rendering the Casimir-Polder attraction exerted by the lens on the atom negligible. The key properties of the proposed optical trap are its subwavelength dimensions, the tunability of the trapping frequency, the facile translation of the trap without moving the lens, and the potential for creating an array of traps. We also study the ground state of a cesium Bose-Einstein condensate formed within the proposed trap by solving the corresponding time-independent Gross-Pitaevskii equation.