activated atom

(redirected from excited atom)

ac·ti·vat·ed at·om

an atom possessing supernormal energy as a result of energy inputs.
See also: excited state.
Synonym(s): excited atom
References in periodicals archive ?
The third is stimulated emission also described by Einstein's coefficient [B.sub.12], where a photon of exactly the correct amount of energy passes an excited atom forcing an electron to drop down energy levels and in the process emitting a photon with the same phase, wavelength, frequency and direction of the passing photon.
Nobel laureate Anthony Leggett of the University of Illinois at Urbana-Champaign suggests a specific way to pose the question, one that's not too far from Lawrence and Beams' original approach: "What is the extent of the photon wave packet as it is emitted from the atom?" Multiplying the lifetime of the excited atom by the speed of light gives an answer of around a meter.
Are humans simply the sum of all the atoms (and the related excited atom quantum states) that compose them?
Spontaneous decay of an excited state arises from the interaction between an excited atom or molecule and the ground state of the quantized electromagnetic field [1].
In 2000, atomic physicist Chris Greene of JILA and the University of Colorado at Boulder and colleagues predicted the existence of a Rydberg molecule made up of an excited atom and a neutral atom.
The next excited atom traversing the cavity interacts with this photon, emitting a photon of its own, and so on.
Physicists generally regard the emission of light by an excited atom as a random process.
Such a structure would prevent an excited atom embedded within it from spontaneously emitting a photon, in effect greatly prolonging the time an atom could spend in an excited state.
The excited atom immediately reemits some light, and because of the superposition or linkage, the wavelengths that each of the two states might emit separately are combined in an interference or beat signal like two sound waves beating together.