How to quantum mechanically describe the photon?

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SUMMARY

The discussion focuses on the quantum mechanical description of photons, specifically the momentum eigenfunctions. To accurately describe monochromatic light, participants emphasize the need to quantize the electromagnetic field, which is covered in quantum field theory and quantum optics textbooks. Key concepts include the creation and annihilation operators for photons, which yield momentum eigenfunctions and coherent states. Recommended resources include David Tong's lecture notes on quantum field theory and Steven Weinberg's "The Quantum Theory of Fields."

PREREQUISITES
  • Quantum field theory fundamentals
  • Understanding of momentum eigenstates
  • Familiarity with creation and annihilation operators
  • Knowledge of coherent states in quantum mechanics
NEXT STEPS
  • Study David Tong's lecture notes on quantum field theory
  • Read Chapter 2 of Steven Weinberg's "The Quantum Theory of Fields"
  • Explore the vector potential of the electromagnetic field in Lorentz gauge
  • Investigate the concept of helicity in quantum mechanics
USEFUL FOR

Physicists, quantum mechanics students, and researchers interested in the quantum description of light and photon behavior.

Somali_Physicist
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This might sound stupid , but I am wondering how exactly could I describe the momentum eigenfunctions of photons?

EDIT:
to destroy ambiguity, I am searching for a quantum mechanic description of monochromatic light similar to how we represent it classically as:

E-> = a->cos(wt+phi)
 
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Somali_Physicist said:
This might sound stupid , but I am wondering how exactly could I describe the momentum eigenfunctions of photons?
##|p>## :biggrin:
 
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Demystifier said:
##|p>## :biggrin:
more precisely, ##|p\rangle##
 
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witty responses and as true as true can be. does it help our @Somali_Physicist ?
 
A quantum description of photons requires quantizing the electromagnetic field. This is discussed in any textbook on quantum field theory or quantum optics, and in many quantum-mechanics textbooks. This will result in operators that create and destroy photons with definite momentum and polarization. Acting on the vacuum (the state of no particles) with a single-photon creation operator produces a momentum eigenfunction. Acting with the exponential of a creation operator (with a specific coefficient) will create a "coherent state" of photons, all with the same momentum, which is as close as you can get to a classical field in the quantum theory.
 
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Avodyne said:
A quantum description of photons requires quantizing the electromagnetic field. This is discussed in any textbook on quantum field theory or quantum optics, and in many quantum-mechanics textbooks. This will result in operators that create and destroy photons with definite momentum and polarization. Acting on the vacuum (the state of no particles) with a single-photon creation operator produces a momentum eigenfunction. Acting with the exponential of a creation operator (with a specific coefficient) will create a "coherent state" of photons, all with the same momentum, which is as close as you can get to a classical field in the quantum theory.
Thank you
So there is no one liner equation ?

What is your textbook called
 
Somali_Physicist said:
This might sound stupid , but I am wondering how exactly could I describe the momentum eigenfunctions of photons?
Weinberg's "The Quantum Theory of Fields" Chapter 2 has a nice discussion of momentum eigenstates of various particle types.

Demystifier said:
##|p>## :biggrin:
A. Neumaier said:
more precisely, ##|p\rangle##
There should also be helicity right? ##|p,\sigma\rangle##
 
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DarMM said:
There should also be helicity right? ##|p,\sigma\rangle##
Or helicity left, ##|p, - \sigma\rangle ##
 
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Somali_Physicist said:
So there is no one liner equation
The relevant equation is that for the vector potential of the e/m field in Lorentz gauge.
 
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A. Neumaier said:
Or helicity left, ##|p, - \sigma\rangle ##
What's the difference between the left and and right side of the brain? On the right side there is nothing right, while on the left side there is nothing left.
 
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  • #12
Demystifier said:
On the right side there is nothing right, while on the left side there is nothing left.

I prefer this: On the left side there is nothing right, while on the right side there is nothing left.
 
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  • #13
Pony said:
I prefer this: On the left side there is nothing right, while on the right side there is nothing left.
It's not sufficiently paradoxical. A quantum description is not good if it does not look like a paradox. :biggrin:
 
  • #14
It's not even right since on the right hand the thumb is at the left...
 

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