Is the overlap of coherent states circular symmetric?

In summary, the conversation discusses the formation of a coherent state in a spin ##1## system and the calculation of the modulus squared of the overlap of the coherent state with a rotation of the coherent state about the ##x##-axis and the ##z##-axis for various values of ##\theta## and ##\phi##. The resulting plot appears to be circularly symmetric.
  • #1
Danny Boy
49
3
What I am interested in doing, is considering the angular momentum eigenstate for a spin ##1## system: ##|J=1, M=1\rangle = \begin{bmatrix}
1 \\
0 \\
0
\end{bmatrix}##, forming the coherent state ##|CS \rangle = \begin{bmatrix}
0.5 \\
-\frac{i}{\sqrt{2}} \\
-0.5
\end{bmatrix}## by taking the rotation ##\text{exp}(-\frac{i \pi}{2}\hat{J}_x)\begin{bmatrix}
1 \\
0 \\
0
\end{bmatrix} = \begin{bmatrix}
0.5 \\
-\frac{i}{\sqrt{2}} \\
-0.5
\end{bmatrix}##.

I then want to work out the modulus squared of the overlap of the coherent state with a rotation of the coherent state about the ##x##-axis and the ##z##-axis for various values of ##\theta## and ##\phi##: $$|\langle CS| \text{exp}(-i \phi \hat{J}_z) \text{exp}(-i \theta \hat{J}_x)|CS\rangle|^2.$$ The result I get is http://farm5.staticflickr.com/4211/34692246053_e0fd2d7cd8_b.jpg. Is this the type of plot you would have predicted? I would have expected something more circular symmetric?
Thanks for any assistance.
 
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  • #2
Looks quite circular symmetric to me, given that the origin is not in the middle of the figure.
 

1. What are coherent states?

Coherent states are a type of quantum state that is often used to describe the behavior of a quantum system. They are characterized by a well-defined phase and amplitude, and are considered to be classical-like states in quantum mechanics.

2. How do coherent states overlap?

Coherent states overlap when the phase and amplitude of one state match or are similar to the phase and amplitude of another state. This means that they have a similar wavefunction and can interfere constructively or destructively.

3. What is the significance of the overlap of coherent states?

The overlap of coherent states is significant because it allows us to understand and describe the behavior of quantum systems. It also plays a crucial role in experiments and applications involving quantum systems, such as quantum computing and quantum cryptography.

4. Can coherent states overlap with non-coherent states?

No, coherent states can only overlap with other coherent states. This is because coherent states have a well-defined phase and amplitude, while non-coherent states do not. Therefore, they cannot interfere constructively or destructively with each other.

5. How is the overlap of coherent states calculated?

The overlap of coherent states is calculated using the overlap integral, which takes into account the wavefunctions of the two states. It is represented by the Greek letter alpha (α) and can be calculated using the formula: α = e^(-|z1-z2|^2/2), where z1 and z2 are the complex amplitudes of the two coherent states.

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