How to Determine Bound States in a Double Delta-Function Potential?

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SUMMARY

The discussion centers on solving Problem 2.27 from Griffiths' textbook, which involves determining the number of bound states and their associated energies for a double delta-function potential. The potential is defined as V(x) = -α[δ(x+a) + δ(x-a)]. The key steps include solving the Schrödinger equation across three regions and applying boundary conditions to derive the wave functions. The participant faced challenges with algebra and understanding energy solutions, ultimately leading to the need for numerical methods to solve the resulting equations for both even and odd wave functions.

PREREQUISITES
  • Understanding of quantum mechanics principles, particularly the Schrödinger equation.
  • Familiarity with delta-function potentials and their implications in quantum systems.
  • Knowledge of boundary conditions in wave function analysis.
  • Basic proficiency in numerical methods for solving equations.
NEXT STEPS
  • Study the derivation of wave functions for single delta potentials.
  • Learn about numerical methods for solving transcendental equations in quantum mechanics.
  • Explore the concept of bound states in quantum systems and their physical significance.
  • Review the mathematical treatment of discontinuous derivatives in quantum mechanics.
USEFUL FOR

Students of quantum mechanics, particularly those tackling problems involving potential wells, physicists interested in bound state analysis, and educators seeking to enhance their teaching of quantum concepts.

TheFerruccio
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My session expired while typing this post, so this is my second attempt at typing it. I *always* forget to paste into notepad before submitting these darned things.

Homework Statement



Problem 2.27, Griffiths.

Given two delta potential wells at +a and -a, determine the number of bound states, find their associated energies, sketch the wave functions.

Homework Equations



[itex]V(x) = -\alpha\left[\delta\left(x+a\right)+\delta\left(x-a\right)\right][/itex]


The Attempt at a Solution



This is the first problem in the book where I really do not know where to begin. I know that the answer has to be in some form of exp(kt) where k is sqrt(-2*m*E)\hbar.

I vaguely understand the book's process for the logic behind constructing the wave function for a single delta potential well, but clearly not well enough.
 
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Start by solving the Schrödinger equation in the three regions x<-a, -a≤x≤a, and x>a.
 
Thanks for the assistance. All I had to do was solve for a 0 potential and pay attention to the boundary conditions (continuous function, discontinuous derivative by a specific value).

The hard part, after that, was not getting lost in the algebra. I still don't quite understand how to solve for the energy, though. I ended up with two equations that needed numerical solving, one for the even wave function, and one for the odd wave function.

Overall, this problem was a real curve ball, and the specific questions this problem asked were far more confusing to me than any of the others.
 

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