Controlling the Quantum World The Science of Atoms, Molecules, and Photons (2007) / Chapter Skim
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6 Photonics and the Nanoworld
6 Photonics and the Nanoworld
Pages 120-136
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From page 120... ...
This places it between the classical world of microscopic objects such as living cells and the quantum world of atoms and mol ecules. Nanoscale structures are rich in promise for novel AMO research because they have nonintuitive but useful physical, chemical, and biological properties that come from their submicroscopic size.
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From page 121... ...
Photonics nanoworld and the the allure of nanoscience can be understood by considering what happens if a macroscopic gold nugget is divided into ever smaller pieces.1 At first, the piece of gold will retain all of its typical characteristics -- it simply gets smaller. When the pieces reach a few micrometers in size, we are no longer able to distinguish individual particles with our eyes.
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From page 122... ...
controlling Quantum world the FIGURE 6-1 Left: Gold and silver nanoparticles are responsible for some of the beautiful colors in stained glass windows from medieval times. SOURCE: National Gallery of Art, Washington, D.C.
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From page 123... ...
in this section, three different approaches to answering this question are discussed, each of which involves tools from AMo physics: reducing the wavelength, using scanning probe microscopies, and exploiting nanotechnology to build a better microscope. Reducing the Wavelength one route to improved resolution is to reduce the wavelength of the light used for viewing.
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From page 124... ...
the AFM is but one of a wide range of scanning probe microscopies, each of which relies on a different molecular-scale effect for its contrast mechanism. the intermolecular forces and tunneling phenomena that provide the contrast mechanisms for these microscopies can best be understood using concepts from AMo physics.
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From page 125... ...
Photonics nanoworld and the FIGURE 6-2 Visualizing the nanoworld. AFM image of two-dimensional array formed by laser-focused atomic deposition of Cr.
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From page 126... ...
Such StMs have been used to map out the positions of individual atoms on the surface of a crystal, as well as the positions of atoms within a mol ecule. Perhaps even more exciting, the tips of these StMs have been used to move and position individual atoms sitting on a crystal surface, allowing the creation of controlled structures with atomic dimensions.
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From page 127... ...
AMo physics, in particular its insights into the electron-atom and electron-molecule collision processes in the
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From page 128... ...
controlling Quantum world 8 the FIGURE 6-3 The terahertz frontier for negative-index materials. New sources and new applications of terahertz radiation have been forefront activities in AMO science over the past decade, and now this research is making connections to nanoscale materials.
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From page 129... ...
, giving rise to the field of atom nano-optics, a subfield of the extensive domain of research involving the laser control of neutral atoms and molecules. FIGURE 6-4 An array of atom traps.
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From page 130... ...
controlling Quantum world 0 the From the Bottom Up For several decades, AMo physicists and physical chemists have studied how atomic and molecular properties change as one goes from a single atom or molecule to a bulk sample containing many millions of atoms or molecules. the study of clusters of carbon atoms revealed a special stability for the cluster containing 60 atoms.
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From page 131... ...
Potential applications of this technology include studies of cavity quantum electrodynamics and development of quantum optical devices with capabilities such as emitting a single photon on demand. controlling the emission of single photons has been a priority goal for application in quantum encryption systems, as discussed in chapter 7.
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From page 132... ...
quantum cryptography systems rely on photons from attenuated laser pulses as an approximation of the single-photon state. However, the produced state has a nonvanishing probability of containing two or more photons per pulse, leaving such systems susceptible to eavesdropping through a beam splitter attack -- this is what makes the need for advances in single-photon sources for quantum cryptog raphy so important.
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From page 133... ...
today, researchers are exploring further miniaturization to nanometer and even atomic scales. the tiny clouds of ultracold atoms trapped and suspended barely above a semiconductor chip surface can behave as coherent matter waves under the influence of the electromagnetic fields in the microchip circuitry.
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From page 134... ...
Nanotechnology in Medicine AMo researchers are merging state-of-the-art optical physics and nanoscience to make important strides in health and medicine. For example, treating cancer cells without destroying normal tissue has been a long-standing problem in oncology.
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From page 135... ...
Photonics nanoworld and the metal-coated glass shells whose optical properties can be tuned to absorb or scatter specific colors of light (see Figure 6-6)
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From page 136... ...
AMo physics will play an essential role in this exploration and will also reap the benefits of the developments that come from it.
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