Aharonov - Bohm effect exercise

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Discussion Overview

The discussion revolves around solving an exercise related to the Aharonov-Bohm effect, specifically involving particles passing through slits in the presence of a solenoid with a constant current. Participants seek guidance on calculating the vector potential, confirming solutions to the Schrödinger equation, and understanding the implications for the interference pattern on a screen.

Discussion Character

  • Homework-related
  • Technical explanation
  • Exploratory

Main Points Raised

  • One participant requests help in solving the Aharonov-Bohm problem and seeks references for guidance.
  • Another participant suggests starting with the calculation of the vector potential, providing a description of the solenoid's magnetic field and its relation to the vector potential.
  • There is a reiteration of the suggestion to use Stokes' theorem and cylindrical symmetry to find the solution for the vector potential.
  • References to S. Weinberg's Lectures on Quantum Mechanics and Sakurai's Modern Quantum Mechanics are provided as potential resources for further understanding.
  • A participant expresses a specific interest in the latter parts of the exercise, questioning whether the suggested references cover those topics.

Areas of Agreement / Disagreement

Participants generally agree on the need to calculate the vector potential first, but there is no consensus on how to approach the latter parts of the exercise or whether the suggested references adequately cover those aspects.

Contextual Notes

The discussion includes assumptions about the solenoid's properties and the nature of the magnetic field, which may not be fully resolved. There are also unresolved mathematical steps related to the vector potential and its implications for the interference pattern.

dude2
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Does anyone know the answers to this, or can hopefully guide me to a text that will help me solve this aharonov-bohm problem?
Here is the given:
Particles (of mass m, and charge q), are driven through two slits that have distance d between them, in a screen that is far away (L>>d) from the obstacle. Behind the obstacle is a solenoid, tha constant current is flowing through it (I).
a) Calculate the vector potential in the space outside the solenoid. b) Assume that without current, the solution to the Schroedinger equation is of this form:

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Confirm that this:

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will constitute a solution to the equation, in the presence of the EM field
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where Ψο, corresponds to the solution without current.
c) Prove that the interference pattern of the particles in the screen, will move, with the presence of current.
 
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What have you already done towards a solution?
 
Nothing, because i don't know where to start...
I didn't ask for a specific solution.
I just posted this here, in case someonw recognized it and pointed me towards a solution on a book, or rather in some references that would help me reach the solution.
 
Why not begin by finding the vector potential? You have a solenoid, with complex winding current, but its main purpose is to create the magnetic field in a localized region in the XY-plane, and directed out of the page (along Z). You can describe this aptly with a point-like magnetization M=M^zM=Mz^, where current density is then J=∇×MJ=∇×M.

And the vector potential (AA) is:

∇×∇×A=∇×B=μ0J=∇×μ0M∇×∇×A=∇×B=μ0J=∇×μ0M

So a suitable equation is:

∇×A=μ0M∇×A=μ0M

I would suggest using Stockes theorem and cyllindrical symmetry of the solenoid to find the solution
dude2 said:
a) Calculate the vector potential in the space outside the solenoid.
 
Last edited:
Cryo said:
Why not begin by finsing the vector potential? You have a solenoid, with complex winding current, but its main purpose is to create the magnetic field in a localized region in the XY-plane, and directed out of the page (along Z). You can describe this aptly with a point-like magnetization ##\mathbf{M}=M\mathbf{\hat{z}}##, where current density is then ##\mathbf{J}=\boldsymbol{\nabla}\times\mathbf{M}##.

And the vector potential (##\mathbf{A}##) is:

##\boldsymbol{\nabla}\times\boldsymbol{\nabla}\times\mathbf{A}=\boldsymbol{\nabla}\times\mathbf{B}=\mu_0\mathbf{J}=\boldsymbol{\nabla}\times\mu_0\mathbf{M}##

So a suitable equation is:

##\boldsymbol{\nabla}\times\mathbf{A}=\mu_0 \mathbf{M}##

I would suggest using Stockes theorem and cyllindrical symmetry of the solenoid to find the solution
Thanks but for what subquestion of the three, your answer is referring to?
 
dude2 said:
Thanks but for what subquestion of the three, your answer is referring to?

dude2 said:
) Calculate the vector potential in the space outside the solenoid
 
As for references. Have a look in S. Weinberg's Lectures on Quantum Mechanics, Ch 10.4 (NB! Not the field theory book). I think Sakurai's Modern Quantum Mechanics also had a bit on this
 
Thanks! I am mostly interested in the questions b and c though. Does Weinberg contain something about them?
 
Have a look
 
  • #10
Will do sir, thanks!
 

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