# Time derivative of creation/annhilation operators

1. Feb 26, 2013

Basically is it possible to take a time derivative of a creation/annhilation operator?

2. Feb 26, 2013

### Einj

I think that's not possible. If you are talking about creation and annhilation operators usually found in QFT, they live in the momentum space, so they don't depend on x, but on p. However, I am not sure if in some other circumstances this could be possible.

3. Feb 26, 2013

yeah so for eample $\frac{d \hat{a}}{dt}$ would =0 if a was the standard QFT annihilation op