Many particle physics - Hamiltonian for Fermi system

Click For Summary
SUMMARY

The discussion focuses on constructing a Hamiltonian for a fermion system with three energy states, specifically utilizing the framework presented in Mahan's 'Many Particle Physics'. The Hamiltonian is expressed in terms of creation and annihilation operators, represented as H = ℏ∑(n=1 to 3) ω_n(a_n† a_n + 1/2) + M12 + M23 + M13. The eigenvalues of the system are confirmed to be E1, E2, and E3, indicating that the presence of transitions does not alter the eigenvalues.

PREREQUISITES
  • Understanding of quantum mechanics, particularly Hamiltonians
  • Familiarity with fermion systems and their properties
  • Knowledge of creation and annihilation operators
  • Basic concepts of eigenvalues and eigenstates in quantum systems
NEXT STEPS
  • Study the derivation of Hamiltonians for fermionic systems in quantum mechanics
  • Explore the role of creation and annihilation operators in quantum field theory
  • Learn about transition matrix elements and their implications in quantum mechanics
  • Investigate the eigenvalue problem in quantum systems and its applications
USEFUL FOR

This discussion is beneficial for physics students, particularly those studying quantum mechanics and many-body physics, as well as researchers working on fermionic systems and Hamiltonian formulations.

Plaetean
Messages
35
Reaction score
0

Homework Statement


Working through problems in Mahan's 'Many Particle Physics' book, and at the end of the 1st chapter there's a question where we're asked to consider a fermion system with three energy states with eigenvalues E1, E2, E3, and matrix elements M12, M23, M13 which connect them and allow transitions between them.

The question asks us to write down a Hamiltonian for the system in terms of creation and annihilation operators, and then determine the eigenvalues for the system.

Homework Equations

The Attempt at a Solution


I'm really a bit lost as to where to start for this, and all I can really think of doing is writing the standard Hamiltonian for a quantum SHO as a sum over states, but I'm not confident this is remotely right.
<br /> H=\hbar\sum_{n=1}^{3}\omega_n(a_n^\dagger a_n + \frac{1}{2})+M_{12}+M_{23}+M_{13}<br />

Is it the case that the energy eigenvalues will just be E1, E2 and E3, as the fact that transitions can occur doesn't change the actual eigenvalues of the system?

Thanks as always!
 
Physics news on Phys.org
Bump!
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 13 ·
Replies
13
Views
5K
  • · Replies 18 ·
Replies
18
Views
3K
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
17
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K