0
$\begingroup$

When a particle enters an excited state, the energy appears in its quantum wavefunction according to $E = h \nu$.

Does the $E$ in this equation also include kinetic energy, and rest mass energy? Or are they "held" somewhere else? Or are kinetic/mass energy a different framework for looking at the same phenomenon, and if so how do they relate?

Also, if the particle gathers enough excitation energy to escape a potential well, and therefore escapes that well, from which 'budget' is the necessary energy taken - kinetic, frequency or mass; and why?

$\endgroup$
1
  • $\begingroup$ $E = \hbar \nu$ is for photons. Energy of quantum systems is generally more complicated, but the energy can come from a variety of degrees of freedom, kinetic and otherwise. $\endgroup$ Commented Mar 4, 2014 at 23:25

1 Answer 1

2
$\begingroup$
  1. The equation [now corrected] in the question is incorrect by a factor of 2pi, because h-bar should just be h.

  2. The equation is not limited to excited states.

  3. E is the relativistic energy from $E^2 = p^2c^2 + m^2c^4$, where m is the rest mass and p is momentum.

  4. While the equation was originally for photons, De Broglie extended it to all particles in his 1924 PhD thesis.

reference:

http://www.rpi.edu/dept/phys/Dept2/modern-physics/lecture-notes.d/6-Quantum-early.pdf

$\endgroup$
2
  • $\begingroup$ Fixed (1). So by your point (3) you're saying that $E=h \nu$ is another way of looking at kinetic+rest energy. Does that include potential energy as well? $\endgroup$ Commented Mar 5, 2014 at 12:20
  • $\begingroup$ E is the relativistic energy from $E^2 = p^2c^2 + m^2c^4$, where m is the rest mass and p is momentum. Will edit answer to clarify, add reference. $\endgroup$
    – DavePhD
    Commented Mar 5, 2014 at 13:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.