Does the Drude Model Account for J Cross B Force in Hall Conductivity?

Click For Summary
SUMMARY

The discussion centers on the limitations of the Drude model in accounting for the J cross B force in Hall conductivity. It is established that while the Drude model applies to solid states, it is inadequate for plasmas, where Magnetohydrodynamics (MHD) analysis is necessary. The conversation highlights that the Drude model does not predict negative conductivity, as it does not adequately consider the effects of thermal energy in electrons within a plasma. The participants agree that the momentum-magnetic field cross product does not encompass the J cross B force in this context.

PREREQUISITES
  • Understanding of Hall conductivity and its relationship with electric and magnetic fields
  • Familiarity with the Drude model and its assumptions regarding solid-state physics
  • Knowledge of Magnetohydrodynamics (MHD) and its application to plasma physics
  • Concept of Gaussian velocity distribution in particle dynamics
NEXT STEPS
  • Research the principles of Magnetohydrodynamics (MHD) and its applications in plasma physics
  • Study the limitations of the Drude model in various physical contexts
  • Explore the effects of thermal energy on electron behavior in plasmas
  • Investigate the implications of J cross B forces in different conductive materials
USEFUL FOR

Physicists, plasma researchers, and students studying electromagnetism and conductivity in various states of matter.

chandrahas
Messages
72
Reaction score
2
I was thinking about hall conductivity, when this question popped up. If there is a magnetic field and an electric field perpendicular to it, then a hall current is generated since the ions have larger gyro radii compared to electrons. Now this current would produce a J cross B force in the direction of Electric field. this means that if electrons have sufficient thermal energy in a plasma, they can create a current that pushes them in the direction of the electric field. This would result in negative conductivity if it is strong enough right?

But solving the drude model equation doesn't give us and negative conductivity anywhere.

So, I was wondering if the effect is not strong enough to result in negative conductivity or whether the drude model does not consider the J cross B force. I always thought the momentum- magnetic field cross product term was the J cross B force.

Thanks
 
Physics news on Phys.org
chandrahas said:
Now this current would produce a J cross B force in the direction of Electric field. this means that if electrons have sufficient thermal energy in a plasma, they can create a current that pushes them in the direction of the electric field. This would result in negative conductivity if it is strong enough right?
The Drude model assumes a solid state. I would not apply the Drude model to a plasma. In a plasma you must use MHD analysis.
Hot electrons have a wider Gaussian velocity distribution. Only a few will be going against the flow, an equal number will be going faster by a similar amount.
 
  • Like
Likes   Reactions: vanhees71
Baluncore said:
an equal number will be going faster by a similar amount.
Oh, if only we could select those and use them.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
555
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K