Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I am reading QFT by Lancaster and Blundell. In chapter 4 of the book the field operators are introduced:

"Now, by making appropriate linear combinations of operators, specifically using Fourier sums, we can construct operators, called field operators, that create and annihilate particles, but this time they don’t create/annihilate particles in particular momentum states but instead they create/annihilate particles localized at particular spatial locations. Thus the operator defined by

ψ^{†}(x)=I/√ν Σ_{p}a^{†}_{p}e^{-ip.x}"

Won't this violate the uncertainty principle? I thought maybe it just creates the particle, after which the particle obeys the relation, but in the very next example(4.1) they go ahead to find the position and momentum of the particle(which they do accurately it seems?). What am I missing here?

Thank you for your time

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# I Field operators and the uncertainty principle

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**