What are the corrections to the energy in a quantum mechanical system?

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In summary, the conversation discusses a quantum mechanical system with a perturbation H', where H = H0 + H', and the exact eigenenergies are given by E = V_0(1-ε) and E = V_0(1-ε^2). The unperturbed eigenenergies of H0 are E = V_0 and E = V_0. The first order corrections to the eigenenergies of H0 are E = 0 and E = -εV_0. The individual asking the question is unsure of which correction corresponds to which unperturbed energy. It is clarified that since the energies are the same, it does not matter which energy the constants are added to.
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Niles
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Homework Statement


Hi all.

We are looking at a quantum mechanical system, where there is a perturbation H', so H = H0 + H', where H0 is the unperturbed Hamiltonian.

The exact eigenenergies (i.e. the eigenenergies of H) are given by:

[tex]
E = V_0(1-\epsilon) \quad \tex{and}\quad E = V_0(1-\epsilon^2).
[/tex]

So far so good. The eigenenergies of H0 (i.e. the unperturbed eigenenergies) are given by:

[tex]
E = V_0 \quad \tex{and}\quad E = V_0.
[/tex]

The first order corrections to the eigenenergies of H0 are given by: [itex]E=0[/itex] and [itex]E=-\epsilon V_0[/itex].

Here my question: How do I generally know which correction "belongs" to which unperturbed energy?

My book is "Griffiths Intro to QM", so feel free to quote from there: The above example is exercise 6.9.

Thanks in advance.Niles.
 
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  • #2
Ok, I answered this question myself. The energies are the same, so it doesn't matter which energy we add the constants to.
 

FAQ: What are the corrections to the energy in a quantum mechanical system?

What are corrections to the energy in quantum mechanics?

In quantum mechanics, corrections to the energy refer to small changes or adjustments made to the predicted energy levels of a system. These corrections take into account factors such as interactions between particles, external forces, and relativistic effects.

Why are corrections to the energy necessary in quantum mechanics?

Corrections to the energy are necessary in quantum mechanics because the basic equations and principles of the theory do not always accurately predict the behavior of particles in real-world scenarios. These corrections help to refine and improve the predictions of quantum mechanics.

How are corrections to the energy calculated in quantum mechanics?

The calculations for corrections to the energy in quantum mechanics involve complex mathematical equations and techniques, such as perturbation theory. These calculations often require advanced knowledge of mathematical and physical concepts.

What are some examples of corrections to the energy in quantum mechanics?

Some examples of corrections to the energy in quantum mechanics include the Lamb shift, which takes into account the interactions between an electron and its own electromagnetic field, and the Casimir effect, which considers the effects of the vacuum energy on the behavior of particles.

How do corrections to the energy impact our understanding of the physical world?

Corrections to the energy in quantum mechanics have played a crucial role in our understanding of the physical world. They have allowed us to make more precise predictions about the behavior of particles, leading to the development of technologies such as transistors and lasers. They have also helped to refine and expand our understanding of fundamental physical laws and principles.

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