Atom Nanolithography with Atom Pinhole Camera
The most efficient method for controlling the motion of material particles in experimental physics is the use of interaction potentials with electromagnetic fields. The static magnetic and electric interaction potentials are used in the optics of charged particles. In the optics of neutral atoms, the various interaction potentials of atoms with laser and electromagnetic fields are used in addition to the static fields. The effective methods of diffraction, interference, mirror reflection of atoms are implemented in atom optics. 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.In this paper, we experimentally implement another 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. The pinhole camera in optics is a camera without lens. Light forming an image passes through a small hole. In our experiment with the atom pinhole camera the Cr atomic beam passes through a set of holes in a metal mask and thereby forms, by analogy with optics, a glowing object of a given geometry. 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 (thickness 5 mum) placed at a distance of 90 mm 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 = 5mum behind the film.
Laser-Focused Atomic Deposition
The ability to fabricate nanometer-sized structures that are stable in air has the potential to contribute significantly to the advancement of new nanotechnologies and our understanding of nanoscale systems. Laser light can be used to control the motion of atoms on a nanoscopic scale. Chromium atoms were focused by a standing-wave laser field as they deposited onto a silicon substrate. The resulting nanostructure consisted of a series of narrow lines covering 0.4 millimeter by 1 millimeter. Atomic force microscopy measurements showed a line width of 65 � 6 nanometers, a spacing of 212.78 nanometers, and a height of 34 �+ 10 nanometers. The observed line widths and shapes are compared with the predictions of a semiclassical atom optical model.
Diode-laser deceleration and collimation of a rubidium beam
We report the use of frequency-chirped diode lasers to decelerate a thermal atomic beam of Rb and, in a separate experiment, the use of frequency-stabilized diode lasers to collimate the beam with optical molasses. For this we used a 100-mW cw laser-diode array injection locked to light from a low-power, frequency-narrowed, single-stripe diode laser. Also, a novel scheme for imaging the neutral-atom beam profile has been developed for monitoring the collimation experiments in two dimensions. We have increased both beam brightness and intensity by a factor of more than 20.