Seriously stuck 3D Quantum Harmonic Oscillator

In summary, the conversation is about a problem from Sakurai 2nd edition, problem 3.21, which involves writing a spherical state in terms of the cartesian degenerate states. The person speaking is unsure how to find the coefficients and suggests finding the matrix that represents ##\hat{L}_z## and diagonalizing it.
  • #1
Xyius
508
4

Homework Statement


The question is from Sakurai 2nd edition, problem 3.21. (See attachments)

*******
EDIT: Oops! Forgot to attach file! It should be there now..
*******

The Attempt at a Solution


Part a, I feel like I can do without too much of a problem, just re-write L as L=xp and then re-write x and p in terms of the raising and lowering operators. Part B is where I have no idea.

It says to write |01m> in TERMS of the eigenstates in cartesian coordinates. So I figure for q=0, l=1 the energy in spherical coordinates is..

[tex]E=\frac{5}{2}\hbar \omega[/tex]

So, obtaining this energy in cartesian coordinates, we can have..

[tex](n_x , n_y , n_z) = (1 0 0) OR (0 1 0) OR (0 0 1)[/tex]

Since in the rectangular coordinate system

[tex]
E=(n_x+n_y+n_z+3/2)\hbar \omega
[/tex]

So if we were to write the spherical state in terms of the cartesian degenerate states, I would assume that would mean..

[tex]|0 1 0>_S=A|1 0 0>_C+B|0 1 0>C + C|0 0 1>_C[/tex]

Where subscript C = Cartesian basis and subscript S = spherical basis.

Am I on the right track here? Because In order to find the coefficients I need to compute (for example)

[tex]A=_S<1 0 0|0 1 0>_C[/tex]

And I am not sure how to do that!
 

Attachments

  • stuck.png
    stuck.png
    24.3 KB · Views: 847
Physics news on Phys.org
  • #2
Hi, I am actually stuck on this problem at a similar state. I was curious if you were able to find a solution or any material covering this problem.
 
  • #3
Try finding the matrix that represents ##\hat{L}_z## with respect to the cartesian basis and diagonalizing it.
 

FAQ: Seriously stuck 3D Quantum Harmonic Oscillator

What is a 3D Quantum Harmonic Oscillator?

A 3D Quantum Harmonic Oscillator is a theoretical model used in quantum mechanics to describe the behavior of a particle in a three-dimensional space under the influence of a harmonic potential. It is a simplified mathematical representation of a physical system that helps us understand the behavior of quantum particles.

What does it mean to be "seriously stuck" in a 3D Quantum Harmonic Oscillator?

Being "seriously stuck" in a 3D Quantum Harmonic Oscillator means that the particle is trapped in a specific region of the potential energy surface and cannot escape. This can happen when the particle's energy is lower than the potential energy at that point, causing it to be confined and unable to move freely.

How does a 3D Quantum Harmonic Oscillator differ from a classical harmonic oscillator?

A classical harmonic oscillator follows the laws of classical mechanics, while a 3D Quantum Harmonic Oscillator follows the laws of quantum mechanics. This means that the particle's position and momentum cannot be known with certainty and are described by a probability distribution. Additionally, in a quantum oscillator, the energy levels are discrete rather than continuous like in a classical oscillator.

What are some real-life applications of a 3D Quantum Harmonic Oscillator?

One of the most well-known applications of a 3D Quantum Harmonic Oscillator is in the field of quantum computing. The behavior of quantum particles in a harmonic potential can be used to manipulate and store information, making it a crucial component in quantum computing systems. It is also used in studying the behavior of atoms and molecules in chemical reactions and in the design of materials with unique electronic and magnetic properties.

What are the limitations of the Seriously stuck 3D Quantum Harmonic Oscillator model?

The Seriously stuck 3D Quantum Harmonic Oscillator model is a simplified representation of a physical system and therefore has limitations. It does not take into account external factors such as interactions with other particles or the effects of relativity. Additionally, it assumes that the potential energy is perfectly symmetric, which may not be the case in real-life situations.

Back
Top