Bose-Einstein condensate sub-wavelength confinement via superoscillations

TL;DR

This paper theoretically demonstrates that superoscillations can enable sub-wavelength confinement of Bose-Einstein condensates in optical lattices by optimizing optical potential parameters.

Contribution

It introduces a novel method using superoscillations and numerical optimization to achieve sub-wavelength BEC confinement in optical lattices.

Findings

Superoscillatory regions contain multiple density peaks at sub-wavelength spacing.

Numerical optimization of optical potential phases and amplitudes enables superoscillation generation.

Superoscillations provide a new route for sub-wavelength BEC confinement in blue-detuned lattices.

Abstract

Optical lattices are essential tools in ultra-cold atomic physics. Here we demonstrate theoretically that sub-wavelength confinement can be achieved in these lattices through superoscillations. This generic wave phenomenon occurs when a local region of the wave oscillates faster than any of the frequencies in its global Fourier decomposition. To illustrate how sub-wavelength confinement can be achieved via superoscillations, we consider a one-dimensional tri-chromatic optical potential confining a spinless Bose-Einstein Condensate of $^{87}$Rb atoms. By numerical optimization of the relative phases and amplitudes of the optical trap's frequency components, it is possible to generate superoscillatory spatial regions. Such regions contain multiple density peaks at sub-wavelength spacing. This work establishes superoscillations as a viable route to sub-wavelength BEC confinement in blue-detuned optical lattices.