Calculating the Energy Spectrum in a Hamiltonian: Tips and Techniques?

  • Thread starter Thread starter babylonia
  • Start date Start date
  • Tags Tags
    Energy Spectrum
Click For Summary
SUMMARY

This discussion focuses on the numerical calculation of the energy spectrum for a Hamiltonian, specifically in the context of periodic and disordered potentials. The Hamiltonian presented is \(\widehat{H}=-\frac{\partial^{2}}{\partial x^{2}}+cos(x)+V(x)\). To compute the energy spectrum, it is essential to expand the wavefunction in a basis of differentiable functions, transforming the differential equation into a matrix eigenvalue problem. Utilizing a matrix eigenvalue routine will yield the desired energy spectrum, although care must be taken to select an appropriate basis to avoid truncation issues in disordered potentials.

PREREQUISITES
  • Understanding of Hamiltonian mechanics
  • Familiarity with matrix eigenvalue problems
  • Knowledge of numerical methods for differential equations
  • Experience with wavefunction expansion techniques
NEXT STEPS
  • Research matrix eigenvalue routines in numerical libraries such as NumPy or SciPy
  • Explore wavefunction expansion techniques in quantum mechanics
  • Study the implications of basis choice in disordered potentials
  • Learn about numerical methods for solving differential equations in quantum systems
USEFUL FOR

Quantum physicists, computational scientists, and researchers working on numerical simulations of quantum systems, particularly those dealing with Hamiltonians in periodic and disordered potentials.

babylonia
Messages
9
Reaction score
0
Hi everyone,

I'm having some problems with this topic. how to numerically calculate the energy spectrum for a certain Hamiltonian? eg., in a periodic potential or disordered potential:
\widehat{H}=-\frac{\partial^{2}}{\partial x^{2}}+cos(x)+V(x)

Thanks for your time and attention.
 
Physics news on Phys.org
Expand your wavefunction in a basis of differentiable functions, and then you will convert your differential equation into a matrix eigenvalue equation. From there, use any matrix eigenvalue routine to get your energy spectrum.
 
Hi Kanato,

Thanks for reply.

Still I'm not clear with which basis it is appropriate to calculate the E(k) spectrum in disordered potential, since there may be a trucation problem in numerical implementation. Is there any special technique?

Best regards
 
Last edited:

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
6
Views
4K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
1K
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
19
Views
3K