What is the Exponential Function in Quantum Mechanics?

In summary, the student is trying to understand how the exponential function works with no boundaries and the teacher provides a potential solution. The student needs to determine the energy of the state and also find the value of "b" in the exponential.
  • #1
whitegirlandrew
10
0

Homework Statement


The question is here.
http://postimg.org/image/l7aw07sr9/

Homework Equations

The Attempt at a Solution


I don't even understand what it's asking because how can a stationary state be an exponential function with no boundaries? I would appreciate any insight, thank you.
 
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  • #2
whitegirlandrew said:

Homework Statement


The question is here.
http://postimg.org/image/l7aw07sr9/

Homework Equations

The Attempt at a Solution


I don't even understand what it's asking because how can a stationary state be an exponential function with no boundaries? I would appreciate any insight, thank you.
I am not sure what you mean by "no boundaries". The wave function must be zero at x=0 and it must go to zero sufficiently fast at x = infinity, and what is provided fulfills those two conditions.

The first step is to determine if this is a state of definite energy (an eigenstate of the hamiltonian). It is, the eigenvalue will give the energy. Do you see how to check if it's an eigenstate?
 
  • #3
nrqed said:
I am not sure what you mean by "no boundaries". The wave function must be zero at x=0 and it must go to zero sufficiently fast at x = infinity, and what is provided fulfills those two conditions.

The first step is to determine if this is a state of definite energy (an eigenstate of the hamiltonian). It is, the eigenvalue will give the energy. Do you see how to check if it's an eigenstate?
We did not go over those concepts.
 
  • #4
whitegirlandrew said:
We did not go over those concepts.
Have you learned about Schrodinger's equation or the hamiltonian?
 
  • #5
nrqed said:
Have you learned about Schrodinger's equation or the hamiltonian?

We learned about schrodinger's equation. It's a second year course so it doesn't deal with the pure mathematics of solving the equation but we went through on how it was 'derived', and various solutions such as the infinite and finite potential well.
 
  • #6
whitegirlandrew said:
We learned about schrodinger's equation. It's a second year course so it doesn't deal with the pure mathematics of solving the equation but we went through on how it was 'derived', and various solutions such as the infinite and finite potential well.
Ok, good. Then all you have to do is to plug the wave function they give into Schrodinger's equation (using for V(x) the potential they give) and then isolate E. That will give you the energy of that state.
 
  • #7
nrqed said:
Ok, good. Then all you have to do is to plug the wave function they give into Schrodinger's equation (using for V(x) the potential they give) and then isolate E. That will give you the energy of that state.
Then what about the integral given below? What does that have to do with anything.
 
  • #8
whitegirlandrew said:
Then what about the integral given below? What does that have to do with anything.
The integral will be needed to determine the constant "A", you will need to impose that the integral of ##|\psi|^2 dx ## from 0 to infinity gives 1 and that will fix the value of A. Note that in the first step, when you plug in the wave function in the equation, the A will cancel out everywhere so in that step you will not fix the value of A.

I must correct one thing: when you plug in the wave function in Schrodinger's equation, you will also be able to determine the value of "b" that appears in the exponential, so at that stage you will be able to determine both E and b.
 
  • #9
nrqed said:
The integral will be needed to determine the constant "A", you will need to impose that the integral of ##|\psi|^2 dx ## from 0 to infinity gives 1 and that will fix the value of A. Note that in the first step, when you plug in the wave function in the equation, the A will cancel out everywhere so in that step you will not fix the value of A.

I must correct one thing: when you plug in the wave function in Schrodinger's equation, you will also be able to determine the value of "b" that appears in the exponential, so at that stage you will be able to determine both E and b.
I Think i somewhat understand, I will give it a try, thank you for the help.
 
  • #10
whitegirlandrew said:
I Think i somewhat understand, I will give it a try, thank you for the help.
You are very welcome. If you get stuck, post here what you tried.
 

1. What is Quantum Mechanics?

Quantum Mechanics is a branch of physics that studies the behavior and interactions of particles at the atomic and subatomic levels. It seeks to explain the fundamental nature of matter and energy, and how they behave in the quantum realm.

2. What is a Quantum Mechanics problem?

A Quantum Mechanics problem is a mathematical or conceptual question that requires the application of principles and theories from Quantum Mechanics to find a solution. These problems often involve understanding the behavior of particles, calculating probabilities, or predicting the outcomes of experiments.

3. What are some real-world applications of Quantum Mechanics?

Quantum Mechanics has many practical applications, including the development of technologies such as transistors, lasers, and MRI machines. It also plays a crucial role in fields such as cryptography, quantum computing, and quantum teleportation.

4. Why is Quantum Mechanics important?

Quantum Mechanics is essential for understanding the behavior of matter and energy at the smallest scales, where classical physics principles do not apply. It has also led to groundbreaking discoveries and advancements in technology, making it a crucial area of study for scientists and engineers.

5. Are there any current challenges or open questions in Quantum Mechanics?

Yes, there are still many unanswered questions and ongoing challenges in the field of Quantum Mechanics. Some of these include reconciling Quantum Mechanics with Einstein's theory of general relativity, understanding the nature of dark matter and energy, and developing a unified theory of quantum gravity.

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