The magic wavelength (also known as a related quantity, magic frequency) is the wavelength of an optical lattice where the polarizabilities of two atomic clock states have the same value, such that the AC Stark shift caused by the laser intensity fluctuation has no effect on the transition frequency between the two clock states. [1] [2]
The laser field in an optical lattice induces an electric dipole moment in the atoms to exert forces on them and hence confine them. However, the difference in polarizabilities of the atomic states leads to an AC Stark shift in the transition frequency between the two states, a shift that is dependent on the laser optical intensity at the particular atom location in the lattice. [1] When it comes to precise measurements of transition frequency such as atomic clocks, the temporal fluctuations of the laser optical intensity would then deteriorate the clock accuracy. Furthermore, due to the spatial variation of laser intensity in the lattice, the atom's motion within the lattice would also be coupled into the uncertainty of the internal transition frequency of the atom.
Despite having different function forms, the polarizabilities of two atomic states do have a dependency on the wavelength of the laser field. In some cases, it is then possible to find a particular wavelength at which the two atomic states happen to have exactly the same polarizability. This particular wavelength, where the AC Stark shift vanishes for the transition frequency, is called the magic wavelength, and the frequency that corresponds to this wavelength is called the magic frequency. This idea was first introduced by Hidetoshi Katori's calculation in 2003, [1] and then experimentally achieved by Katori's group in 2005. [2]
Spectroscopy is the general field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO)
Optical tweezers are scientific instruments that use a highly focused laser beam to hold and move the microscopic and sub-microscopic objects like atoms, nanoparticles and droplets, in a manner similar to tweezers. If the object is held in air or vacuum without additional support, it can be called optical levitation.
In the field of optics, transparency is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale, the photons can be said to follow Snell's Law. Translucency allows light to pass through, but does not necessarily follow Snell's law; the photons can be scattered at either of the two interfaces, or internally, where there is a change in index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with the overall appearance of one color, or any combination leading up to a brilliant spectrum of every color. The opposite property of translucency is opacity.
Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum.
Resolved sideband cooling is a laser cooling technique allowing cooling of tightly bound atoms and ions beyond the Doppler cooling limit, potentially to their motional ground state. Aside from the curiosity of having a particle at zero point energy, such preparation of a particle in a definite state with high probability (initialization) is an essential part of state manipulation experiments in quantum optics and quantum computing.
Resonance Raman spectroscopy is a Raman spectroscopy technique in which the incident photon energy is close in energy to an electronic transition of a compound or material under examination. The frequency coincidence can lead to greatly enhanced intensity of the Raman scattering, which facilitates the study of chemical compounds present at low concentrations.
An optical lattice is formed by the interference of counter-propagating laser beams, creating a spatially periodic polarization pattern. The resulting periodic potential may trap neutral atoms via the Stark shift. Atoms are cooled and congregate at the potential extrema. The resulting arrangement of trapped atoms resembles a crystal lattice and can be used for quantum simulation.
A magneto-optical trap (MOT) is an apparatus which uses laser cooling and a spatially-varying magnetic field to create a trap which can produce samples of cold, trapped, neutral atoms. Temperatures achieved in a MOT can be as low as several microkelvin, depending on the atomic species, which is two or three times below the photon recoil limit. However, for atoms with an unresolved hyperfine structure, such as , the temperature achieved in a MOT will be higher than the Doppler cooling limit.
An atomic line filter (ALF) is a more effective optical band-pass filter used in the physical sciences for filtering electromagnetic radiation with precision, accuracy, and minimal signal strength loss. Atomic line filters work via the absorption or resonance lines of atomic vapors and so may also be designated an atomic resonance filter (ARF).
In spectroscopy, the Autler–Townes effect, is a dynamical Stark effect corresponding to the case when an oscillating electric field is tuned in resonance to the transition frequency of a given spectral line, and resulting in a change of the shape of the absorption/emission spectra of that spectral line. The AC Stark effect was discovered in 1955 by American physicists Stanley Autler and Charles Townes.
A nuclear clock or nuclear optical clock is a notional clock that would use the frequency of a nuclear transition as its reference frequency, in the same manner as an atomic clock uses the frequency of an electronic transition in an atom's shell. Such a clock is expected to be more accurate than the best current atomic clocks by a factor of about 10, with an achievable accuracy approaching the 10−19 level. The only nuclear state suitable for the development of a nuclear clock using existing technology is thorium-229m, a nuclear isomer of thorium-229 and the lowest-energy nuclear isomer known. With an energy of about 8 eV, the corresponding ground-state transition is expected to be in the vacuum ultraviolet wavelength region around 150 nm, which would make it accessible to laser excitation. A comprehensive review can be found in reference.
Sisyphus cooling is a type of laser cooling of atoms used to reach temperatures below the Doppler cooling limit. This cooling method was first proposed by Claude Cohen-Tannoudji in 1989, motivated by earlier experiments which observed sodium atoms cooled below the Doppler limit in an optical molasses. Cohen-Tannoudji received part of the Nobel Prize in Physics in 1997 for his work. The technique is named after Sisyphus, a figure in the Greek mythology who was doomed, for all eternity, to roll a stone up a mountain only to have it roll down again whenever he got it near the summit.
Photoelectrochemical processes are processes in photoelectrochemistry; they usually involve transforming light into other forms of energy. These processes apply to photochemistry, optically pumped lasers, sensitized solar cells, luminescence, and photochromism.
An atomic clock is a clock that measures time by monitoring the frequency of radiation of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions between such states they interact with a very specific frequency of electromagnetic radiation. This phenomenon serves as the basis for the International System of Units' definition of a second:
The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency , the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s−1.
A quantum clock is a type of atomic clock with laser cooled single ions confined together in an electromagnetic ion trap. Developed in 2010 by physicists as the U.S. National Institute of Standards and Technology, the clock was 37 times more precise than the then-existing international standard. The quantum logic clock is based on an aluminium spectroscopy ion with a logic atom.
A Zeeman slower is a scientific apparatus that is commonly used in quantum optics to cool a beam of atoms from room temperature or above to a few kelvins. At the entrance of the Zeeman slower the average speed of atoms is on the order of a few hundred m/s. The spread of velocity is also in the order of a few hundred m/s. Final speed at the exit of the slower is few 10 m/s with an even smaller spread.
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National Laboratory of Atomic, Molecular and Optical Physics is the national inter-university research center with the headquarters at Institute of Physics of Nicolaus Copernicus University in Toruń, Poland. Established in 2002, the Laboratory is focused on atomic, molecular, and optical physics (AMO).
Hidetoshi Katori, is a Japanese physicist and professor at the University of Tokyo best known for having invented the magic wavelength technique for ultra precise optical lattice atomic clocks. Since 2011, Katori is also Chief Scientist at the Quantum Metrology Lab, RIKEN.
The I. I. Rabi Prize in Atomic, Molecular, and Optical Physics is given by the American Physical Society to recognize outstanding work by mid-career researchers in the field of atomic, molecular, and optical physics. The award was endowed in 1989 in honor of the physicist I. I. Rabi and has been awarded biannually since 1991.
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