Recoil temperature

Energy imparted to an atom by photon emission

In condensed matter physics and atomic physics, the recoil temperature is a fundamental lower limit of temperature attainable by some laser cooling schemes. It is the temperature corresponding to the kinetic energy imparted to an atom decaying from an excited electronic state at rest to a lower energy electronic state by the spontaneous emission of a photon. This is a consequence of the conservation of momentum, the atom having momentum of equal magnitude in opposite direction to the emitted photon. The recoil temperature is

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