An electron cannot remain in an excited state indefinitely with constant energy input. Instead, it will transition to higher energy states upon absorbing energy, or return to a lower state if energy is removed. Devices like lasers and LEDs utilize this principle by manipulating electron states through precise energy inputs. Continuous energy input leads to ionization of the atom or molecule, and practical applications require careful consideration of quantum state manipulations, such as Rabi cycling, which necessitates matching the frequency of energy input to the transition frequency of the electron.
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An electron bound to an atom or molecule can only increase its energy in discrete quanta. The classical notion of continuous energy input does not apply at the atomic or molecular level.medammari said:TL;DR Summary: what will happened if I keep giving the same amount of energy, constant in time to an electron?
There was a post recently about some clever idea to prevent radioactive decay by almost continuously resetting the quantum state of the object by repeated measurements - but I can't find the thread.medammari said:Will it stay at the excited state forever
If you keep giving the electron more energy, then eventually you will ionise the atom or molecule.medammari said:what will happened if I keep giving the same amount of energy, constant in time to an electron? Will it stay at the exited state forever
I guess you mean the thread: Geiger counters and measurement. We certainly had fun. Just like this thread, it was a question from a first time poster. But were allowed to have fun and dive into those technical details, because the thread level was "I: intermediate".PeroK said:There was a post recently about some clever idea to prevent radioactive decay by almost continuously resetting the quantum state of the object by repeated measurements - but I can't find the thread.
Except that lasers have to work with more than one excited state, both for theoretical and practical reasons. And LED's just work like a waterfall, no need to bring the water back up to the higher level, new water at the higher level will keep floating in anyway.Drakkith said:You could, however, make it jump to an excited state, wait for it to transition back down, and then make it jump back up to its excited state again. This is how several devices such as lasers and LED's work.
Giving the same amount of energy to the same electron is only possible in a thought experiment. In actual practical devices (and also in real experiments), more manipulations of details of quantum states of small systems like molecules, ions, electrons, or even photons are possible, compared to what a layman or even a physics freshman would believe. But still, there remain fundamental restrictions of which manipulations are possible ("for theoretical and practical reasons"), just like in the case of lasers.medammari said:what will happened if I keep giving the same amount of energy, constant in time to an electron
Sure. but this still only work if the frequency matches that of the transition frequency between the ground and exitcted state.Hyperfine said:
That is certainly true. Given the original question, I leapt to the conclusion that a resonant transition was a possibility, and certainly not totally irrelevant to the response provided by Drakkith.f95toli said:Sure. but this still only work if the frequency matches that of the transition frequency between the ground and exitcted state.
Under "normal" situations (i.e. the field is not extremely strong) nothing will happens if that is not the case.