Ground State Symmetry of Single Electron w/ Non-Interacting 2nd Electron

In summary, for a symmetrical potential with one electron, the wavefunctions can either be symmetric or antisymmetric. The ground state wavefunction is symmetric because it has the smallest average energy, with only one hump, allowing for a smaller kinetic energy. Adding a second non-interacting electron with spin 1/2 will result in the same wavefunction as the first electron. This is because in 1-D, the Schrodinger equation has been solved and the bound states obtained, making the ground state symmetric.
  • #1
positron
21
0
for a symmetrical potential with one electron, i know that the wavefunctions are symmetric or antisymmetric. for the ground state why is the wavefunction symmetric?

Also, if you add a second electron that is non-interacting, (why) does it have the same wavefunction as the first electron?
 
Last edited:
Physics news on Phys.org
  • #2
I assume we are talking 1d here? So you've solved the 1d Schrodinger equation and have obtained the bound states of the system, right? You've put your first electron into the ground state, now what is the lowest energy single particle state available to the next electron? (Hint: the electron has spin 1/2)
 
  • #3
Physics Monkey said:
I assume we are talking 1d here? So you've solved the 1d Schrodinger equation and have obtained the bound states of the system, right? You've put your first electron into the ground state, now what is the lowest energy single particle state available to the next electron? (Hint: the electron has spin 1/2)

Yes, the problem is in 1-D. The potential is a general symmetric potential, so we don't know necessarily have an actual analytical solution to Schrodinger equation. So how do we know the ground state must be symmetric, and that if we put another electron in the potential, it has the same wave function?
 
  • #4
positron said:
for a symmetrical potential with one electron, i know that the wavefunctions are symmetric or antisymmetric. for the ground state why is the wavefunction symmetric?

An intuitive explanation:

It's because the ground state has the smallest average energy. Energy in QM comes from two places, potential energy and kinetic energy. If you look at the form of the KE operator you will see that KE is smallest when your wave function slope is least (more flat). So the ground state only has one hump. That is, the more humps you got the more you have to go up and down and the higher the slopes.

Carl
 

1. What is the ground state symmetry of a single electron with a non-interacting second electron?

The ground state symmetry of a single electron with a non-interacting second electron is described by the Pauli exclusion principle, which states that no two electrons can occupy the same quantum state. This means that the two electrons must have opposite spins, resulting in a total spin of zero.

2. How does the ground state symmetry affect the behavior of the electrons?

The ground state symmetry of the electrons dictates their behavior in terms of their spin and energy levels. The Pauli exclusion principle ensures that the electrons remain in their lowest possible energy state, known as the ground state, and that their spins are opposite to each other.

3. Can the ground state symmetry change?

The ground state symmetry of the electrons is a fundamental property of quantum mechanics and cannot be changed. As long as the electrons are non-interacting, they will maintain their opposite spins and remain in their ground state.

4. How is the ground state symmetry related to the stability of atoms?

The ground state symmetry plays a crucial role in the stability of atoms. Without the Pauli exclusion principle, electrons would be able to occupy the same quantum state, leading to unstable and unpredictable behavior. The ground state symmetry ensures that electrons are distributed in a stable manner, making atoms more stable.

5. Are there any exceptions to the ground state symmetry of non-interacting electrons?

There are some exceptions to the ground state symmetry of non-interacting electrons, such as in the case of superconductors. In superconductors, electrons form pairs with opposite spins, breaking the ground state symmetry. However, this is a special case and does not apply to most non-interacting electrons.

Similar threads

  • Quantum Physics
Replies
2
Views
761
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Quantum Physics
2
Replies
44
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
73
  • Quantum Physics
Replies
13
Views
2K
  • Quantum Physics
Replies
3
Views
2K
  • Atomic and Condensed Matter
Replies
0
Views
477
  • Advanced Physics Homework Help
Replies
6
Views
2K
  • Quantum Physics
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
1K
Back
Top