- #1
daudaudaudau
- 297
- 0
How do I express an arbitrary 2-particle state in second quantization? I could write this
<br /> |\psi\rangle=\sum_{mn}c_{mn} a_m^\dagger a_n^\dagger |0\rangle<br />
where c_{mn} is a constant, a_n^\dagger is the creation operator and |0\rangle is the vacuum state. The only problem is that I want to sum over all PAIRS, and when I write the sum like this, all pairs are included twice, which is a mess.
<br /> |\psi\rangle=\sum_{mn}c_{mn} a_m^\dagger a_n^\dagger |0\rangle<br />
where c_{mn} is a constant, a_n^\dagger is the creation operator and |0\rangle is the vacuum state. The only problem is that I want to sum over all PAIRS, and when I write the sum like this, all pairs are included twice, which is a mess.
