How to evaluate this nabla expression in spherical coordinates?

Click For Summary
SUMMARY

This discussion focuses on evaluating the expression (\vec{A}\cdot\nabla)\Psi in spherical coordinates, specifically in the context of the Schrödinger equation for a proton in a constant magnetic field. The gradient operator in spherical coordinates is defined as ##\nabla = \hat{r}\partial_{r} + \frac{1}{r}\hat{\theta}\partial_{\theta} + \frac{1}{r\sin\theta} \hat{\phi}\partial_{\phi}##. The vector potential \vec{A} is expressed as ##A = A^{r}\hat{r} + A^{\theta}\hat{\theta} + A^{\phi}\hat{\phi}##, leading to the operator ##A\cdot \nabla = A^{r}\partial_{r} + \frac{1}{r}A^{\theta}\partial_{\theta} + \frac{1}{r\sin\theta} A^{\phi}\partial_{\phi}##. This formulation allows for the evaluation of the expression in terms of the components of \vec{A} and the derivatives of the scalar function \Psi.

PREREQUISITES
  • Understanding of spherical coordinates and their derivatives
  • Familiarity with vector calculus, specifically the gradient operator
  • Knowledge of the Schrödinger equation and its applications
  • Basic concepts of electromagnetism, particularly vector potentials
NEXT STEPS
  • Study the derivation and applications of the gradient operator in spherical coordinates
  • Explore the implications of vector potentials in quantum mechanics
  • Learn about the mathematical treatment of the Schrödinger equation in different coordinate systems
  • Investigate the role of magnetic fields in quantum systems and their effects on particle behavior
USEFUL FOR

Physicists, particularly those working in quantum mechanics and electromagnetism, as well as students and researchers involved in theoretical physics and mathematical modeling of physical systems.

Izzhov
Messages
120
Reaction score
0
I'm currently working out the Schrödinger equation for a proton in a constant magnetic field for a research project, and while computing the Hamiltonian I came across this expression:

(\vec{A}\cdot\nabla)\Psi

where \Psi is a scalar function of r, theta, and phi. How do you evaluate this expression in spherical coordinates in terms of the components of \vec{A} and derivatives of \Psi?
 
Physics news on Phys.org
We have in spherical coordinates, ##\nabla = \hat{r}\partial_{r} + \frac{1}{r}\hat{\theta}\partial_{\theta} + \frac{1}{r\sin\theta} \hat{\phi}\partial_{\phi}## and ##A = A^{r}\hat{r} + A^{\theta}\hat{\theta} + A^{\phi}\hat{\phi}## so the operator is just ##A\cdot \nabla = A^{r}\partial_{r} + \frac{1}{r}A^{\theta}\partial_{\theta} + \frac{1}{r\sin\theta} A^{\phi}\partial_{\phi}##
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
7K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
4K