Tough Perturbation Question (At least for me)

  • Context: Graduate 
  • Thread starter Thread starter Ed Quanta
  • Start date Start date
  • Tags Tags
    Perturbation
Click For Summary
SUMMARY

The discussion centers on applying time-independent degenerate perturbation theory to a particle in a two-dimensional square well, specifically addressing the perturbation \( H' = 10^{-3}E_1 \sin\left(\frac{\pi x}{a}\right) \). The eigenstates are given by \( P\psi_{np} = \frac{2}{a} \sin\left(\frac{n\pi x}{a}\right) \sin\left(\frac{p\pi y}{a}\right) \) and the energy levels by \( E_{np} = E_1(n^2 + p^2) \). Participants emphasize the need to identify the basis, compute the perturbation matrix, and formulate the system of equations to solve the problem effectively.

PREREQUISITES
  • Understanding of time-independent degenerate perturbation theory
  • Familiarity with quantum mechanics concepts, particularly eigenstates and energy levels
  • Knowledge of perturbation theory applications in quantum systems
  • Ability to manipulate trigonometric functions in mathematical expressions
NEXT STEPS
  • Study the derivation and applications of time-independent degenerate perturbation theory
  • Learn how to compute perturbation matrices in quantum mechanics
  • Explore examples of perturbation theory in two-dimensional quantum wells
  • Review the provided summary link for additional insights on degenerate perturbation theory
USEFUL FOR

Students and professionals in quantum mechanics, particularly those studying perturbation theory, as well as educators looking for practical examples of applying theoretical concepts in two-dimensional quantum systems.

Ed Quanta
Messages
296
Reaction score
0
Consider a particle confined in a two dimensional square well with faces at x=0,a;y=0,a. The doubly degenerate eigenstates appear as Psinp=(2/a)sin(n(pi)x/a)sin(p(pi)x/a)
Enp=E1(n^2 + p^2)

What do these energies become under perturbation H'=10^-3E1sin((pi)x/a)?

Help anyone? No idea how to solve this.
 
Physics news on Phys.org
There's not too much advice to give,just apply the theory strictly.Identify the basis,compute the pertubation matrix and then write the system of equations.

Daniel.
 
Last edited:

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
2
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K