NANO.IL.

All-dielectric Waveguide-overlayer System for Single-atom Optical Trapping

Angeleene ENG Electrooptical Engineering Unit, Ben-Gurion University of the Negev, Beer Sheva, Israel Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel Center for Quantum Information Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel "Nanooptomechanics” Laboratory, ITMO University, St. Petersburg, Russia

Strong light-atom interactions can be utilized for applications toward quantum information storage and processing. Despite the maturity of research towards trapping of atoms using optical lattices, these laser set-ups tend to be large and complex. In contrast, integrated photonics can be used to provide modular compact platforms. In this work, we propose a waveguide-overlayer system for trapping cold atoms above planar all-dielectric waveguides.

We choose blue and red-detuned laser relative to the D-line of atomic Rb and launch the bi-chromatic light into our waveguide, which is composed of a Si3N4 core placed on a SiO2 substrate. The overlayer is a single silicon subwavelength antenna which enhances the evanescent field of the system. This device can become a method of realizing an improved version of previously-proposed integrated atom chips, as part of a building block for integrated atom optics, with applications such as high-precision sensors and implementations towards quantum information processing. Similar methods have been proposed in literature using plasmons, however, these methods require the use of metals such as gold. Our all-dielectric system aims to produce the same effect while reducing the thermal noise produced by heating metals and absorption due to losses.

Our numerical simulations show that with the bi-chromatic input on both sides of the waveguide, the overlayer generates a focused evanescent field above the surface. We then calculated the potential due to this field and found a potential well along the axis perpendicular to the waveguide, forming an optical atomic trap. We also considered the contribution of the atom-surface potentials – the Casimir-Polder and van der Waals potentials. These traps are tight enough for single-atom confinement; this system provides possibilities for creating an array of single-atom traps with lattice constants that can be selected by fabricating an appropriate waveguide-overlayer system.









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