https://en.formulasearchengine.com/w/api.php?action=feedcontributions&feedformat=atom&user=KirkHolcombeformulasearchengine - User contributions [en]2026-08-02T12:30:27ZUser contributionsMediaWiki 1.47.0-wmf.7https://en.formulasearchengine.com/w/index.php?title=Main_Page&diff=49613Main Page2014-08-13T07:36:55Z<p>KirkHolcombe: </p>
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<div>{{Refimprove|date=December 2009}}<br />
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[[Image:Resolved sideband cooling.jpg|400px|right|Resolved sideband cooling]]<br />
'''Resolved sideband cooling''' is a [[laser cooling]] technique that can be used to cool strongly trapped atoms to the quantum [[ground state]] of their motion. The atoms are usually precooled using the [[Doppler cooling|Doppler]] [[laser cooling]]. Subsequently the resolved [[sideband]] cooling is used to cool the atoms beyond the [[Doppler cooling limit]].<br />
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A cold trapped atom can be treated to a good approximation as a [[quantum mechanical]] [[harmonic oscillator]]. If the spontaneous decay rate is much smaller than the vibrational frequency of the atom in the trap, the [[energy level]]s of the system can be resolved as consisting of internal levels each corresponding to a ladder of vibrational states.<br />
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Suppose a two-level atom whose ground state is shown by ''g'' and excited state by ''e''. Efficient laser cooling occurs when the frequency of the laser beam is tuned to the red sideband i.e.<br />
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<math>\omega = \omega_{0} - \nu</math>,<br />
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where <math>\omega_{0}</math> is the internal atomic transition frequency and <math>\nu</math> is the harmonic oscillation frequency of the atom. In this case the atom undergoes the transition<br />
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<math>\vert g, n \rangle \rightarrow \vert e, n-1 \rangle</math>,<br />
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where <math>\vert a, m \rangle</math> represents the state of an ion whose internal atomic state is ''a'' and the motional state is ''m''. This process is labeled '1' in the image to the right.<br />
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Subsequent [[spontaneous emission]] occurs predominantly at the carrier frequency if the recoil energy of the atom is negligible compared with the vibrational quantum energy i.e.<br />
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<math>\vert e, n-1 \rangle \rightarrow \vert g, n-1 \rangle.</math><br />
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This process is labeled '2' in the image to the right.<br />
The average effect of this mechanism is cooling the ion by one vibrational energy level. When these steps are repeated a sufficient number of times <math>\vert g,0 \rangle</math> is reached with a high probability.<ref>A.SCHLIESSER,R. RIVIÈRE, G. ANETSBERGER, O. ARCIZET,T. J. KIPPENBERG [http://www.nature.com/nphys/journal/v4/n5/full/nphys939.html "Resolved-sideband cooling of a micromechanical oscillator"], nature physics, Vol 4 MAY 2008.</ref><br />
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==References==<br />
{{Reflist}}<br />
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==See also==<br />
* [[Laser cooling]]<br />
* [[Amplitude modulation]]<br />
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{{DEFAULTSORT:Resolved Sideband Cooling}}<br />
[[Category:Atomic physics]]<br />
[[Category:Plasma physics]]<br />
[[Category:Cooling technology]]<br />
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[[ru:Охлаждение методом боковой полосы]]</div>KirkHolcombe