Modified Harmonic Oscillator probabilities

In summary: You'll need to go back to the original expression and substitute the new y value to get the modified equation for psi_0. Then, to find the expansion coefficients, you'll need to use the orthogonality relation to solve for the coefficients c_n.
  • #1
ma18
93
1

Homework Statement



The e-functions for n=0,1,2 e-energies are given as

psi_0 = 1/(pi^1/4 * x0^1/2)*e^(x^2/(2*x0^2)

psi_1 =...

psi_2 =...

The factor x0 is instantaneously changed to y= x0/2. This means the initial wavefunction does not change.

Find the expansions coefficients of the initial state to the three lowest states of the modified potential. What energy measurements would you find and with what probability.

Homework Equations



Prob En = c_n ^2

En = hbar*omega*(n+0.5)

The Attempt at a Solution



I can find the new energies:

En = hbar*omega*(n+0.5) = m*omega^2*x_0^2*(n+1/2)

Putting in y = x_0 instead we get:

En = m*omega^2*y^2*(n+1/2)
= 1/4 m*omega^2*x_0^2*(n+1/2)
= 1/4 hbar*omega*(n+0.5)For the expansion coefficients I am not sure what to put into the formula:

cn = integral from -inf to inf: phi* * psi dx

I know that the modified eqn to psi_0 is:

psi_m0 = sqrt(2)*e^2 * psi_0

But if I put this in I just get sqrt(2)*e^4 and that doesn't make sense for the probs (>1)
 
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  • #2
ma18 said:
the e-functions for n=0,1,2 e-energies are given as

psi_0 = 1/(pi^1/4 * x0^1/2)*e^(x^2/(2*x0^2)

psi_1 =...

Psi_2 =...

The factor x0 is instantaneously changed to y= x0/2. This means the initial wavefunction does not change.
Yes, assuming that ##\dot{x}_0## = 0. Otherwise the phase shift will change.
ma18 said:
Find the expansions coefficients of the initial state to the three lowest states of the modified potential. What energy measurements would you find and with what probability.

Homework Equations



prob en = c_n ^2

en = hbar*omega*(n+0.5)

The Attempt at a Solution



i can find the new energies:

En = hbar*omega*(n+0.5) = m*omega^2*x_0^2*(n+1/2)

putting in y = x_0 instead we get:

En = m*omega^2*y^2*(n+1/2)
= 1/4 m*omega^2*x_0^2*(n+1/2)
= 1/4 hbar*omega*(n+0.5)


for the expansion coefficients i am not sure what to put into the formula:

Cn = integral from -inf to inf: Phi* * psi dx
Is this a typo? ##\Psi^* \Psi##
ma18 said:
i know that the modified eqn to psi_0 is:

Psi_m0 = sqrt(2)*e^2 * psi_0

but if i put this in i just get sqrt(2)*e^4 and that doesn't make sense for the probs (>1)

Honestly I'm not sure what you're trying to do, if that was supposed to be a complex conjucate (that's what it looks like to me) Your psi functions are real, so... Again, though, I really don't know what your trying to do. I'm not going to guarantee to be able to help you, but could you give a clearer explanation of the problem?

It almost looks as thought you're trying to normalize a function to solve for the coefficients, but I'm not sure.
 
  • #3
ma18 said:
I know that the modified eqn to psi_0 is:

psi_m0 = sqrt(2)*e^2 * psi_0

This isn't correct. You can't factor out e2 like that.
 

1. What is a Modified Harmonic Oscillator?

A Modified Harmonic Oscillator is a type of oscillator system that deviates from a simple harmonic oscillator by having additional forces acting on it, such as friction or external driving forces.

2. How do probabilities play a role in Modified Harmonic Oscillators?

In a Modified Harmonic Oscillator, probabilities play a role in determining the likelihood of the oscillator being in a particular state or position at a given time. These probabilities are calculated using mathematical equations and can be used to predict the behavior of the oscillator over time.

3. What factors affect the probabilities in a Modified Harmonic Oscillator?

The probabilities in a Modified Harmonic Oscillator are affected by various factors, including the initial conditions of the oscillator, the strength of the external forces, and the damping or friction present in the system. These factors can alter the shape and frequency of the oscillations and, in turn, impact the probabilities of the oscillator being in different states.

4. How are Modified Harmonic Oscillator probabilities experimentally determined?

Modified Harmonic Oscillator probabilities can be experimentally determined by measuring the position and velocity of the oscillator at different points in time and then using these values to calculate the probabilities using the appropriate equations. These experiments can also involve changing the external forces or other parameters and observing how they affect the probabilities of the oscillator being in different states.

5. What applications do Modified Harmonic Oscillator probabilities have in science and engineering?

The study of Modified Harmonic Oscillator probabilities has many applications in science and engineering. For example, understanding these probabilities can help in the design of mechanical systems, such as springs and pendulums, and can also be applied in fields such as quantum mechanics and molecular dynamics simulations.

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