The atomic de Broglie microscope (also atomic nanoscope, neutral beam microscope, or scanning helium microscope when

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

is used as the probing atom) is an imaging system which is expected to provide resolution at the nanometer scale. It is sometimes referred to as a "nanoscope."

History

The resolution of optical microscopes is limited to a few hundred nanometers by the wave properties of the light. The idea of imaging with atoms instead of light is widely discussed in the literature since the past century.

Atom optics Atom optics (or atomic optics) is the area of physics which deals with beams of cold, slowly moving neutral atoms, as a special case of a particle beam. Like an optical beam, the atomic beam may exhibit diffraction and interference, and can be focu ...

using neutral atoms instead of light could provide resolution as good as the

electron microscope An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...

and be completely non-destructive, because short wavelengths on the order of a nanometer can be realized at low energy of the probing particles. "It follows that a helium microscope with nanometer resolution is possible. A helium atom microscope will be unique non-destructive tool for reflection or transmission microscopy."

Focusing of neutral atoms

Currently, the atom-optic imaging systems are not competitive with electron microscopy and various types of near-field probe. The main problem in the optics of atomic beams for an imaging system is the focusing element. There is no material transparent to the beam of low-energy atoms. A

Fresnel zone plate A zone plate is a device used to Focus (optics), focus light or other things exhibiting wave character.G. W. Webb, I. V. Minin and O. V. Minin, “Variable Reference Phase in Diffractive Antennas”, ''IEEE Antennas and Propagation Magazine'', ...

and

evanescent field In electromagnetics, an evanescent field, or evanescent wave, is an oscillating electric and/or magnetic field that does not propagate as an electromagnetic wave but whose energy is spatially concentrated in the vicinity of the source (oscillati ...

lens were suggested, as well as various atomic mirrors. Such mirrors use the

quantum reflection Quantum reflection is a uniquely quantum phenomenon in which a compact object, such as a neutron or a small molecule, reflects smoothly and in a wavelike fashion from a much larger surface, such as a pool of mercury. In contrast, a classically beha ...

by Casimir–van der Waals potential tails.

Ridged mirrors

Recently, the performance of solid-state atomic mirrors was greatly enhanced with so-called

ridged mirror In atomic physics, a ridged mirror (or ridged atomic mirror, or Fresnel diffraction mirror) is a kind of atomic mirror, designed for the specular reflection of neutral particles (atoms) coming at a grazing incidence angle. In order to reduce the ...

s (or Fresnel diffraction mirrors). The

specular reflection Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surf ...

of an atomic wave from a

can be interpreted as spatial Zeno effect. At the appropriate ellipsoidal profile, such a mirror could be used for focusing of an atomic beam into a spot of some tens of nanometers; the scattering of atoms from this spot brings the image of the object, like in the scanning

confocal microscope Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a sp ...

, scanning electron microscope, or scanning probe microscopy. The scheme shown in the picture is one possibility. A similar scheme is posted at the homepage of the University of Cambridge;Atom Optics and Helium Atom Microscopy. Cambridge University, see an additional list of references there. Such an imaging system could also be realized with

holographic Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other applications. In principle, i ...

, Fresnel diffraction, and evanescent wave systems. Some of such systems may become competitive with established methods of visualization and measuring of nano-objects. See the overview at Nanowiki ( Nanotechnology).

References

{{DEFAULTSORT:Atomic De Broglie Microscope Microscopes Nanotechnology Atomic, molecular, and optical physics

History

Focusing of neutral atoms

Ridged mirrors

See also

References