Atom Pinhole Camera

The most difficult problem in atom optics is the problem of high-resolution focusing of neutral atoms, which is promising for the nondestructive method for probing the surface at the atomic level, as well as for the creation of nanostructures on the surface. Although there are many proposals for focusing of atomic beams, this problem is experimentally unsolved. The main difficulty is the creation of the interaction potential of the atom with the electromagnetic field that is close to an "ideal" lens for atoms.

We developed a new approach to the problem of focusing and construction of an image in atom optics, which is based on a well known idea of "optical pinhole camera" (Fig.1) . The pinhole camera in optics is a camera without a lens. Light forming an image passes through a pin hole.

In our experiment with the atom pinhole camera (Fig.2) the atomic beam passes through a set of holes in a metal mask (Fig.3) and thereby forms, by analogy with optics, a "glowing" object of a given geometry (Fig.4). The atoms pass through the holes in the mask, propagate in vacuum along rectilinear trajectories, similar to light rays, and are incident on a thin film placed at a distance L from the mask with a large number (n =10⁷–10⁸ /cm²) of nanoholes (50 nm diameter). Each hole of the film is a pinhole camera for atoms, which forms its individual image of the object on the substrate surface placed at a distance of l behind the film. In this geometry, a set of the images of the object, which are decreased by a factor of about m = L / l ~ 10000 this leads to a decrease in the profile height of the created nanostructures at a given exposition.[1]

Fig.1 Optical Pinhole Camera	Fig.2 Atom Pinhole Camera
Fig.3 The mask in the form of greak letter Lambda	Fig.4 One of ten million identical nanostructures made with the mask lambda

Next figures (Fig.5, Fig.6) shows the detailed image of a simple cross. As seen in the figures, the cross consists of the nanostructures that are images of the object mask.

Fig.6 Three of the 107 images of the "cross"

Fig.7 The surface section (800 x 800 nm) with the image of the "cross" object

 

References:

1. V. I. Balykin, P. A. Borisov, V. S. Letokhov, P. N. Melent’ev, S. N. Rudnev, A. P. Cherkun, A. P. Akimenko, P. Yu. Apel’, and V. A. Skuratov, "Atom "Pinhole Camera" with Nanometer Resolution", JETP Letters, Vol. 84, No. 8, pp. 466–469, (2006)