Doppler coolingDoppler cooling is a mechanism that can be used to trap and slow the motion of atoms to cool a substance. The term is sometimes used synonymously with laser cooling, though laser cooling includes other techniques. HistoryDoppler cooling was simultaneously proposed by two groups in 1975, the first being David J. Wineland and Hans Georg Dehmelt and the second being Theodor W. Hänsch and Arthur Leonard Schawlow.
Laser coolingLaser cooling includes several techniques where atoms, molecules, and small mechanical systems are cooled with laser light. The directed energy of lasers is often associated with heating materials, e.g. laser cutting, so it can be counterintuitive that laser cooling often results in sample temperatures approaching absolute zero. It is routinely used in atomic physics experiments where the laser-cooled atoms are manipulated and measured.
Magneto-optical trapIn atomic, molecular, and optical physics, 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 neutral atoms. Temperatures achieved in a MOT can be as low as several microkelvins, depending on the atomic species. A MOT is formed from the intersection of the zero of a weak quadrupolar magnetic field and six circularly polarizedred-detunedoptical molasses beams.
Optical pumpingOptical pumping is a process in which light is used to raise (or "pump") electrons from a lower energy level in an atom or molecule to a higher one. It is commonly used in laser construction to pump the active laser medium so as to achieve population inversion. The technique was developed by the 1966 Nobel Prize winner Alfred Kastler in the early 1950s. Optical pumping is also used to cyclically pump electrons bound within an atom or molecule to a well-defined quantum state.
Boltzmann constantThe Boltzmann constant (kB or k) is the proportionality factor that relates the average relative thermal energy of particles in a gas with the thermodynamic temperature of the gas. It occurs in the definitions of the kelvin (K) and the molar gas constant, in Planck's law of black-body radiation and Boltzmann's entropy formula, and is used in calculating thermal noise in resistors.
Hyperfine structureIn atomic physics, hyperfine structure is defined by small shifts in otherwise degenerate electronic energy levels and the resulting splittings in those electronic energy levels of atoms, molecules, and ions, due to electromagnetic multipole interaction between the nucleus and electron clouds.
Kinetic energyÉmilie du Châtelet (1706–1749) was the first to publish the relation for kinetic energy Ekin∝mv2{\displaystyle E_{\text{kin}}\propto mv^{2}}, derived from the experimental observation of objects dropped into clay. (Portrait by Maurice Quentin de La Tour.)In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion.
Zeeman effectThe Zeeman effect (Dutch: [ˈzeːmɑn]) is the splitting of a spectral line into several components in the presence of a static magnetic field. It is caused by the interaction of the magnetic field with the magnetic moments of the atomic electrons associated with their orbital motion and spin; this interaction shifts some orbital energies more than others, resulting in the split spectrum.
National Institute of Standards and TechnologyThe National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement.
Gaithersburg, MarylandGaithersburg ( GAY-thərz-burg) is a city in Montgomery County, Maryland, United States. At the time of the 2020 United States census, Gaithersburg had a population of 69,657, making it the third-largest incorporated city and the ninth-most populous community in the state. Gaithersburg is located to the northwest of Washington, D.C., and is considered a suburb and a primary city within the Washington metropolitan area.
Planck constantThe Planck constant, or Planck's constant, denoted by h{\displaystyle h}, is a fundamental physical constant of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and a particle's momentum is equal to the wavenumber of the associated matter wave (the reciprocal of its wavelength) multiplied by the Planck constant.
Time of flightTime of flight (ToF) is the measurement of the time taken by an object, particle or wave (be it acoustic, electromagnetic, etc.) to travel a distance through a medium. This information can then be used to measure velocity or path length, or as a way to learn about the particle or medium's properties (such as composition or flow rate).*As an Amazon Associate I earn from qualifying purchases.