PDA

View Full Version : definition of fermionic annihilation operators


malcomson
May9-11, 06:33 AM
Hi, I'm revising for an exam and I came across a past paper that has a question on annihilation operators, It asks what happens when acting on a wavefunction with a group of different creation/annhilation operators (all identical fermions..

It's quite simple apart from the fact that it includes both spin up and spin down options and in my notes I only have a simplified case of all spin up fermions.

My question is, if the annihilation operator ai is has the constants (-1)^n1+n2+...+ni-1 times ni where n1 etc are the occupancies of each state. Does this include both spin states of should I treat them as separate sets.

I think I should include both spins as that would give the anticommutation relations between operators of different spins, allowing antisymmetry of a function under the interchange of two particles of opposing spin but I'm not really confident about it.

Apologies if unclear, am yet to figure out putting equations in posts.