# Aharonov bohm effect

1. Jan 26, 2009

### spidey

I am confussed with aharonov bohm effect. i read the wikipedia article.

http://en.wikipedia.org/wiki/Aharonov-Bohm_effect

it says "enclosed magnetic field" but "magnetic field is zero"

It says "different electric potentials" but "electric field is zero"

2. Jan 26, 2009

### Staff: Mentor

"enclosed magnetic field" means the field inside the solenoid. The field is zero outside the solenoid.

The electric field is zero when the electric potential is uniform (does not vary with position). In the second case, there are two regions, each with uniform (but different) electric potential. For example, one region might have a uniform potential of 5 volts, and the other one might have a potential of 10 volts. The electric field is zero in both regions.

3. Jan 26, 2009

### spidey

Even before placing placing the solenoid the magnetic field is zero. After the placing the solenoid also magnetic field is zero.Then, why there is phase shift?

4. Jan 26, 2009

### Hans de Vries

There is a magnetic vector potential A around the solenoid which goes with 1/r.
The magnetic field B is the curl of this field and happens to be zero. The phase
shift depends on the vector potential A (not the magnetic field B)

http://www.physics-quest.org/Book_Lorentz_force_from_Klein_Gordon.pdf

see section 11.2

Regards, Hans

Last edited: Jan 26, 2009