Harmonic Oscillator: Lowest Allowed Energy Not E=0?

In summary, the lowest allowed energy for the Harmonic Oscillator is not E=0, but rather a definite minimum value of E=E0. This is due to the quantization of energy and the boundary conditions set by the Time Independent Schrodinger equation. The permissible energy levels are given by E_n = (n+1/2)hbar * omega, and having E=0 would contradict Heisenberg's uncertainty principle.
  • #1
asdf1
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why is the lowest allowed energy not E=0 but some definite minimum E=E0?
 
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  • #2
If you solve the Time Independent Schrodinger equation for the Harmonic Oscillator, that is
[tex] -\frac{\hbar^2}{2m} \frac{d^2\Psi}{dx^2} + \frac{1}{2}kx^2 \Psi = E \Psi [/tex]

The quantization of energy comes from the boundary conditions (ie, [itex] \Psi = 0 [/itex] when [itex] x= \infty [/itex] or [itex] x = -\infty [/itex]).

The permitted energy levels will be

[tex] E_n = (n+\frac{1}{2}) \hbar \omega [/tex]

So the lowest Energy is not E=0.
 
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  • #3
I could give a hand-wave argument. We have E=1/2mv^2+1/2kx^2.
If E=0 both x and v are zero, which contradicts Heisenberg.
 
  • #4
thank you very much! :)
 

1. What is a harmonic oscillator?

A harmonic oscillator is a type of physical system that exhibits periodic motion. It is characterized by a restoring force that is proportional to the displacement from its equilibrium position.

2. What is the lowest allowed energy in a harmonic oscillator?

The lowest allowed energy in a harmonic oscillator is the ground state energy, which is the lowest energy level that the system can have. It is represented by the quantum number n=0 and is not equal to zero.

3. How is the lowest allowed energy in a harmonic oscillator different from other energy levels?

The lowest allowed energy is different from other energy levels because it is the only one that does not have any nodes in the wave function. This means that the probability of finding the particle at the equilibrium position is the highest for the ground state energy.

4. How is the lowest allowed energy in a harmonic oscillator related to the uncertainty principle?

The uncertainty principle states that there is a fundamental limit to the precision with which certain pairs of physical properties of a particle, such as its position and momentum, can be known simultaneously. The ground state energy in a harmonic oscillator is the energy state with the lowest possible uncertainty, meaning that the position and momentum of the particle are known with the highest precision.

5. Can the lowest allowed energy in a harmonic oscillator be zero?

No, the lowest allowed energy in a harmonic oscillator cannot be zero. This is because the potential energy of the system must be greater than zero in order for the particle to be confined to the harmonic oscillator potential well. Therefore, the ground state energy cannot be equal to zero.

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