Quantum jump

<h2 id="atomic-electron-transition">Atomic electron transition</h2>
<p class="note">Main article: <a href="/facts/Atomic_electron_transition/HeaF4JJk">Atomic electron transition</a></p>

<p>Atomic electron transitions cause the emission or absorption of <a href="/facts/Photon/mFNhAEzA">photons</a>. Their statistics are <a href="/facts/Poisson_distribution/CvCzXkHr">Poissonian</a>, and the time between jumps is <a href="/facts/Exponential_distribution/yY3EdV0u">exponentially distributed</a>.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> The damping time constant (which ranges from <a href="/facts/Nanosecond/gARLTp4c">nanoseconds</a> to a few seconds) relates to the natural, pressure, and field <a href="/facts/Spectral_line/HuI4Bj5f">broadening of spectral lines</a>. The larger the energy separation of the states between which the electron jumps, the shorter the <a href="/facts/Wavelength/kcJU0ymz">wavelength</a> of the photon emitted.
</p>

<p>In an <a href="/facts/Ion_trap/L1m5HBMU">ion trap</a>, quantum jumps can be directly observed by addressing a trapped ion with radiation at two different frequencies to drive electron transitions.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> This requires one strong and one weak transition to be excited (denoted 
  
    
      
        ω
      
    
    {\displaystyle \omega }
  
12 and 
  
    
      
        ω
      
    
    {\displaystyle \omega }
  
13 respectively in the figure to the right). The electron energy level, 
  
    
      
        
          |
        
        2
        ⟩
      
    
    {\displaystyle |2\rangle }
  
, has a short lifetime, 
  
    
      
        Γ
      
    
    {\displaystyle \Gamma }
  
2 which allows for constant emission of photons at a frequency 
  
    
      
        ω
      
    
    {\displaystyle \omega }
  
12 which can be collected by a camera and/or <a href="/facts/Photomultiplier_tube/bjbB9fBE">photomultiplier tube</a>. State  
  
    
      
        
          |
        
        3
        ⟩
      
    
    {\displaystyle |3\rangle }
  
 has a relatively long lifetime 
  
    
      
        Γ
      
    
    {\displaystyle \Gamma }
  
3 which causes an interruption of the photon emission as the electron gets shelved in state through application of light with frequency  
  
    
      
        ω
      
    
    {\displaystyle \omega }
  
13.  The ion going dark is a direct observation of quantum jumps.
</p>
<h2 id="molecular-electronic-transition">Molecular electronic transition</h2>
<p class="note">Main article: <a href="/facts/Molecular_electronic_transition/EeRT45sP">Molecular electronic transition</a></p>

<h2 id="sources">Sources</h2>
<ul><li><a href="http://www.mikomma.de/schroe/quantumjumps.htm">Are there quantum jumps?</a></li>
<li>«<a href="http://www.rzuser.uni-heidelberg.de/~as3/no-quantum-jumps.pdf">There are no quantum jumps, nor are there particles!</a>» by H. D. Zeh, <i>Physics Letters</i> A172, 189 (1993).</li>
<li>Gleick, James Gleick (October 21, 1986). <a href="https://www.nytimes.com/1986/10/21/science/physicists-finally-get-to-see-quantum-jump-with-own-eyes.html">"Physicists Finally Get To See the Quantum Jump"</a>. <i>New York Times</i>. New York City. Retrieved 2013-08-23.</li>
<li><a href="http://www.mikomma.de/fh/hydrod/h71.html">Der Quantensprung im Bohrschen Atommodell</a> Frühe Quantenphysik</li>
<li><a href="http://www.zeit.de/1996/19/quanten.txt.19960503.xml">Der Quantensprung</a> Die zweifelhafte Karriere eines Fachausdrucks (ZEIT 1996)</li>
<li><a href="http://www.arxiv.org/abs/quant-ph/9702007">M.B. Plenio und P.L. Knight <i>The Quantum Jump Approach to Dissipative Dynamics in Quantum Optics</i></a>, vgl. auch Rev. Mod. Phys. 70 101–144 (1998). (Beschreibung der Dynamik offener Systeme mittels Quantensprüngen)</li>
<li><a href="http://www.mikomma.de/soqsp/soqsp.htm">Historisches zum Quantensprung</a>, Sommerfeld und Einstein 1911</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Deléglise, S. "Observing the quantum jumps of light" (PDF). Archived from the original (PDF) on November 7, 2010. Retrieved September 17, 2010. <a href="https://web.archive.org/web/20101107043403/http://www.mpq.mpg.de/Theorygroup/CIRAC/wiki/images/8/86/Samuel.pdf" target="_blank">https://web.archive.org/web/20101107043403/http://www.mpq.mpg.de/Theorygroup/CIRAC/wiki/images/8/86/Samuel.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Foot, C. J. (2005). Atomic physics. Oxford: Oxford University Press. ISBN 978-0-19-152314-4. OCLC 181750270. <a href="978-0-19-152314-4" target="_blank">978-0-19-152314-4</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
</ol>

Quantum jump open-in-new

Quantum jump