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
330px, Different lengths as in respect to the molecular scale.
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...
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
330px, Different lengths as in respect to the molecular scale.
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...
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
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 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 mirror In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon waf ...
s.
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 mirror In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon waf ...
s 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
In optics, the Fresnel diffraction equation for near-field diffraction is an approximation of the Kirchhoff–Fresnel diffraction that can be applied to the propagation of waves in the near field. It is used to calculate the diffraction pattern ...
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
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave ...
from a
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 ...
can be interpreted as spatial
Zeno effect
The quantum Zeno effect (also known as the Turing paradox) is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting.
Som ...
.
At the appropriate
ellipsoid
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...
al 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
Scan may refer to:
Acronyms
* Schedules for Clinical Assessment in Neuropsychiatry (SCAN), a psychiatric diagnostic tool developed by WHO
* Shared Check Authorization Network (SCAN), a database of bad check writers and collection agency for bad ...
.
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
In optics, the Fresnel diffraction equation for near-field diffraction is an approximation of the Kirchhoff–Fresnel diffraction that can be applied to the propagation of waves in the near field. It is used to calculate the diffraction pattern ...
, and
evanescent wave
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 ...
systems. Some of such systems may become competitive with established methods of visualization and measuring of nano-objects. See the overview at
Nanowiki (
Nanotechnology
Nanotechnology, also shortened to nanotech, is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal o ...
).
See also
*
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 ...
*
Atomic mirror In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon waf ...
*
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 ...
*
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 ...
*
Grazing angle
*
Zeno effect
The quantum Zeno effect (also known as the Turing paradox) is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting.
Som ...
*
Matter wave
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave ...
*
Scanning helium ion microscope
A scanning helium ion microscope (SHIM, HeIM or HIM) is an imaging technology based on a scanning helium ion beam. Similar to other focused ion beam techniques, it allows to combine milling and cutting of samples with their observation at sub-nan ...
(SHIM, HeIM or HIM)
References
{{DEFAULTSORT:Atomic De Broglie Microscope
Microscopes
Nanotechnology
Atomic, molecular, and optical physics