Two particles in a potential (wave equation and harmonic oscillators)

In summary, the conversation discusses a problem involving the harmonic oscillator and the wave function for two particles with the same mass and potential energy. The total energy of the system is given, and the conversation explores whether a specific state is allowed for both identical and different particles. The problem also mentions the time independent schrodinger wave equation and the concept of degenerate states.
  • #1
Psycopathak
13
0
Homework Statement

Please bear with me, I'm not that good with LaTeX.

Consider the harmonic oscillator problem. Define [tex]\Phi[/tex]n(x) as the n-th wave function for one particle, with coordinate x and energy (n+1/2) [tex]\overline{h}[/tex][tex]\omega[/tex], where n=0, 1,… Now, let’s consider a system consisting of two particles which have the same mass; each particle experiences the same potential energy function and therefore each has the same angular frequency [tex]\omega[/tex]. Consider a situation where the total energy of this two-particle system is Etotal = 3 [tex]\overline{h}[/tex][tex]\omega[/tex]. We write the wave functions [tex]\Psi[/tex](xA,xB) for the system of two particles, where xA and xB are the positions of the two particles.
You will be asked below whether the following state is (or is not) allowed; it is a product of two n=1 wave functions (one for each particle):
[tex]\Psi[/tex]maybe(xA,xB) =[tex]\Phi[/tex]1(xA)[tex]\Phi[/tex]1(xB)

(a) Suppose first that the particles are of different species, called A and B. Is the state [tex]\Psi[/tex]maybe(xA,xB) an allowed state of the two-particle system, or not?

(b) For this “different species case”, what is the degeneracy g of the 2-particle system with total energy Etotal=3 [tex]\overline{h}[/tex][tex]\omega[/tex]?

(c) Now, consider instead the case when both particles are identical bosons. Is the state labeled [tex]\Psi[/tex]maybe(xA,xB) possible, or not?



Homework Equations



From what I know, the time independent schrodinger wave equation.

H[tex]\Psi[/tex] = (-h/2m)([tex]\partial[/tex]2/[tex]\partial[/tex]x2) + V[tex]\Psi[/tex] = E[tex]\Psi[/tex]

Right Moving particle solution
[tex]\Psi[/tex](x) = Aexp(ipx)/[tex]\overline{h}[/tex])

E = p2/2m + C


The Attempt at a Solution



I am pretty confused with what this problem is asking, so I don't have an attempt at a solution to offer. I figured that if you have [tex]\Psi[/tex]maybe(xa,xb) could be looked at as:
[tex]\Psi[/tex](xa) * [tex]\Psi[/tex](xb)

Unfortunately from here, I am really not sure where to go on. I've been reading this problem for a week with no such luck.
 
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  • #2
For b), you should use the fact that E=3hw=(n+1/2)hw+(m+1/2)hw=(m+n+1)hw, so if I am not mistaken degenrate state is one which for two different eigenvalues we have the same energy, i.e check for values of m and n which satisfy n+m+1=3 and partition the ways to choose them, for example, n=0 and m=2 and n=2 and m=0 are two non degenrate states, the degenrate state is n=m=1, and thus g=?
 

1. What is the wave equation and how does it relate to two particles in a potential?

The wave equation is a mathematical expression that describes the behavior of waves in a given system. In the context of two particles in a potential, the wave equation is used to determine the probabilities of finding each particle at different positions in the potential. It takes into account the potential energy of the system, as well as the mass and momentum of the particles.

2. What is a harmonic oscillator and how does it relate to two particles in a potential?

A harmonic oscillator is a system that exhibits oscillatory motion around a stable equilibrium point. In the context of two particles in a potential, this can refer to the behavior of the particles as they move in a potential energy well. The particles will oscillate back and forth around the equilibrium point, with their motion being described by the wave equation.

3. How is the behavior of two particles in a potential affected by the shape of the potential energy well?

The shape of the potential energy well determines the overall behavior of the particles. If the well is deep and narrow, the particles will have a small range of motion and will exhibit more regular oscillations. If the well is shallow and wide, the particles will have a larger range of motion and may exhibit more chaotic behavior. The shape of the potential well also affects the energy levels of the particles and their probabilities of being found at different positions.

4. Can the wave equation be used to predict the exact positions of the particles in a potential?

No, the wave equation can only give the probabilities of finding the particles at different positions in the potential. The exact positions of the particles cannot be predicted due to the principles of quantum mechanics, which state that the position and momentum of a particle cannot be simultaneously known with absolute certainty.

5. How do interactions between the particles affect their behavior in a potential?

Interactions between the particles, such as repulsion or attraction, can affect their behavior in a potential. For example, if the particles have opposite charges, they will be attracted to each other and will exhibit different oscillatory behavior compared to particles with the same charge. Additionally, interactions can affect the shape and depth of the potential well, altering the overall behavior of the particles in the system.

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