Wave function of two different fermions

In summary, the wave function of two different fermions must be antisymmetric according to quantum field theory. This can be seen in the general state of two fermions, where the wave function f must be antisymmetric due to the fact that {b^\dagger(p_1),b^\dagger(p_2)}=0. However, if the fermions are not identical, the Pauli principle does not apply and there is no possible symmetry to begin with.
  • #1
Marchigno
3
0
Hi! According to quantum field theory, must the wave function of two different fermions be antisymmetric?
If I have a state of two equal fermions: [tex]b^\dagger(p_1)b^\dagger(p_2)|0>[/tex] I can construct the general state of two fermions:
[tex]\int d^3p_1 d^3p_2f(p_1,p_2)b^\dagger(p_1)b^\dagger(p_2)|0>[/tex]
where f is the wave function. Now because [tex]\{b^\dagger(p_1),b^\dagger(p_2)\}=0[/tex]
the wave function f mast be antisymmetric.
The question is: if I now consider two different fermions: [tex]b^\dagger(p_1)d^\dagger(p_1)|0>[/tex]
so that the general state is
[tex]\int d^3p_1 d^3p_2f(p_1,p_2)b^\dagger(p_1)d^\dagger(p_2)|0>[/tex]
because
[tex]\{b^\dagger(p_1),d^\dagger(p_2)\}=0[/tex]
remains true, does it mean the wave function of any two fermions will be antisymmetric? I thought it was true only for two identical particles!
Thank you for the answers! :)
 
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  • #2
If the fermion are not identical, then there is no possible symmetry to start with, so the Pauli principle does not apply.
 

1. What is the wave function of two different fermions?

The wave function of two different fermions is a mathematical representation of the quantum state of the two particles. It describes the probability of finding the particles at a certain position in space at a given time.

2. How is the wave function of two different fermions different from that of two identical fermions?

The wave function of two identical fermions must be antisymmetric, meaning it changes sign under particle exchange, while the wave function of two different fermions can be either symmetric or antisymmetric.

3. Can two different fermions occupy the same quantum state?

No, according to the Pauli exclusion principle, two different fermions cannot occupy the same quantum state simultaneously. This is why the wave function must be antisymmetric for two identical fermions.

4. What is the significance of the wave function of two different fermions?

The wave function of two different fermions is essential in understanding the behavior and interactions of particles in quantum systems. It allows us to calculate the probability of observing certain outcomes in experiments.

5. How is the wave function of two different fermions used in practical applications?

The wave function of two different fermions is used in various fields, such as quantum computing, nuclear physics, and condensed matter physics. It helps in predicting the behavior of particles in these systems and designing new technologies based on quantum principles.

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