A Aharonov - Bohm effect exercise

5
0
246247


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:

246248


Confirm that this:

246249


will constitute a solution to the equation, in the presence of the EM field
246250

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.
 

vanhees71

Science Advisor
Insights Author
Gold Member
12,270
4,622
What have you already done towards a solution?
 
5
0
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.
 

Cryo

Gold Member
169
71
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
a) Calculate the vector potential in the space outside the solenoid.
 
Last edited:
5
0
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 refering to?
 

Cryo

Gold Member
169
71
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
 
5
0
Thanks! I am mostly interested in the questions b and c though. Does Weinberg contain something about them?
 

Cryo

Gold Member
169
71
Have a look
 
5
0
Will do sir, thanks!
 

Want to reply to this thread?

"Aharonov - Bohm effect exercise" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top