Talk:Atomic electron transition

Previous discussion while the article was still titled Quantum leap is now at Talk:Quantum leap.

Physics Stub‑class Mid‑importance

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"few nanoseconds or less"

First, the timing depends on the energy gap value. Second, it is generally not correct to suggest a picture like

the "↑" state before $T 0$
transition started at $T 0$
intermediate state between $T 0$ and $T 1$
transition ended at $T 1$
the "↓" state after $T 1$ .

In the Schrödinger picture, we will always see some superposed state with the ↑ amplitude gradually decreasing and ↓ amplitude increasing. More general, the moment of a transition is always uncertain, and speculation such as "transition started at… and ended at…" do not have a sense. Incnis Mrsi (talk) 20:03, 22 September 2012 (UTC)[reply]

The moment (on the time scale) of a transition is uncertain (Poissonian statistics for a single atom/ion). Nevertheless the time for a transition (jump) is always shorter then statistical period of jumping cycle (interval between jumps) - obtained from density matrix ("superposition"). You can see (experimental - not speculation) it in wiki reference[1] (page 3). The probability for given state is very close to 1 between jumps. It is similar as the radioactive decay. A given (long-living radioactive) nucleus is in an excited state (with probability about 1) until its decay (unpredictable when but statistically predictable from this matrix element). But it does not mean that nucleus is decaying - e.g. millions years - and that we can not say (at any time) what (chemical) element it is (In reality, decay/transition itself is very fast). 195.113.87.138 (talk) 13:09, 2 October 2012 (UTC)[reply]