# Homework Help: Quantum harmonic oscillator in electric field

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1. Nov 9, 2014

### mbijei

1. The problem statement, all variables and given/known data
There is a harmonic oscillator with charge q and sudenly we turn on external electric field E, which direction is the same as oscillator's. We need to find probability, that particles energy calculated in electric field will be in m state.
n=1, m=2

2. Relevant equations

3. The attempt at a solution
So I've solved Schrödinger's equation for harmonic oscillator in electric field and found needed energy eigenvalue, but I don't know how to find probability.

2. Nov 9, 2014

### vela

Staff Emeritus
How do you usually calculate probabilities in quantum mechanics? In other words, if the particle is in state $\lvert \psi \rangle$ and you want to know the probability you'll find it in state $\lvert \phi \rangle$, what do you do?

3. Nov 10, 2014

### mbijei

That's the point, I don't have state vectors ∣ψ⟩ and ∣ϕ⟩. I only have Hamiltonian and energy eigenvalue.

4. Nov 10, 2014

### vela

Staff Emeritus
You said you solved the Schrodinger equation. How can you not have the state vectors?

5. Nov 13, 2014

### laimonel

Could someone PLEASE explain this solution step by step? I have this very same problem (except both n and m are equal to 1) and i cant find any examples how to solve this kind of problems anywhere..

6. Nov 13, 2014

### vela

Staff Emeritus
No, that's not how it works here. We don't provide solutions. You need to try figure it out. That's how you learn.

7. Nov 13, 2014

### laimonel

Well I've been trying since yesterday and I'm pretty frustrated by now. I've searched everywhere for at least one example on how to solve this kind of problem and found nothing. I'm probably not the brightest kid and i seem to be unable to figure it all out just by myself..