Constructing Eigenstate for a given hamiltonian

In summary: You can try to simplify the expression if you want, but you will need to be more specific about what you want to simplify.In summary, the student attempted to solve the H\psi=E\psi equation by finding the eigenvalues and eigenvectors. However, they made a mistake in converting the operator to matrix form and need to solve the time-dependent Schrodinger equation in order to calculate the berry phase.
  • #1
mahondi
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0

Homework Statement


Hi; I am trying to construct eigenstate for the given hamiltonian. I have the energy eigenvalues and corresponding eigenvectors. But How can I construct eigenstates?





Homework Equations





The Attempt at a Solution


I tried to use the H . Psi= E . Psi eigenvalue relation where Psi is the state that I want to construct.Namely, what is the procedure that I should follow. I'm glad if you answer to the question.
 
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  • #2
What is the Hamiltonian you are considering? I can't see it.
 
  • #3
When you solve [itex]H\psi=E\psi[/tex] you will get eigenvalues and what are usually called eigenfunctions or eigenstates. Eigenvectors usually refer to the vectors obtained from the ordinary algebraic eigenvalue problem with a matrix. (i.e. with a matrix corresponding to a system of linear algebraic equations, not differential equations). Maybe you already have the eigenstates, but are calling them the wrong word?
 
  • #4
I attached my detailed problem as a pdf file. Since this is my research project, I constructed Hamiltonian and found its eigenvalues and eigenvectors.In other words, I haven't solved the H . Psi=E . Psi equation yet.And I thought I have to solve Time dependent Schrödinger equation because Hamiltonian in the attachments depend implicitly on time. Now I have to find eigenstates of the hamiltonian to calculate the berry phase.

Sorry for the foggy question.
 

Attachments

  • newfile3.pdf
    64.8 KB · Views: 416
  • #5
That Hamiltonian is not Hermitian, so you made some sort of mistake in converting the operator to matrix form. If you can't find your mistake, post some more details and maybe we can help.

You have solved the [tex]H\psi=E\psi[/tex] equation by finding the eigenvalues and eigenvectors. You do have to use the energy eigenvalues for the states to solve the time-dependent Schrodinger equation

[tex] i\hbar \frac{\partial \psi(t)}{\partial t} = E \psi(t)[/tex]

for the time-dependence of the states. This should give you an equation to solve for [tex]\varphi[/tex]. Again, give it a try and come back with questions.
 
  • #6
Hi, Thank you all.I made a mistake in calculations now my hamiltonian is hermitian and I realized that I have already found the eigenstates by finding eigenvectors of my hamiltonian:)but there is another question that I would like to ask. I want to simplify the expression given in the attachments. I tried to simplify it in mathematica by using TrigFactor code. My question is that Can I make more simplifications to this expression?

Thank you..
 

Attachments

  • newfile4.pdf
    53.2 KB · Views: 305

What is an eigenstate?

An eigenstate, also known as a stationary state, is a quantum state that remains unchanged when acted upon by a given operator. In other words, it is a state in which the observable properties of a system do not change over time.

Why is constructing eigenstates important?

Constructing eigenstates is important because it allows us to understand the behavior of quantum systems and make predictions about their future states. It also helps us to solve complex quantum mechanical problems and determine the energy levels of a system.

What is the role of the Hamiltonian in constructing eigenstates?

The Hamiltonian is an operator in quantum mechanics that represents the total energy of a system. In order to construct eigenstates, we use the Hamiltonian to find the eigenvalues and eigenvectors of a system, which represent the allowed energy states and the corresponding state of the system.

What are the steps involved in constructing eigenstates for a given Hamiltonian?

The first step is to write out the Hamiltonian in terms of the system's variables. Then, we solve the Schrödinger equation to find the eigenvalues and eigenvectors. Next, we normalize the eigenvectors and use them to construct the eigenstates. Finally, we can use these eigenstates to calculate the expected values of observables for the system.

Can any Hamiltonian have eigenstates?

No, not all Hamiltonians have eigenstates. In order for a Hamiltonian to have eigenstates, it must be Hermitian, meaning it is equal to its own conjugate transpose. If a Hamiltonian is not Hermitian, then it will not have well-defined eigenstates.

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