Quantum field theory VS Quantum mechanics

[AleksanderPhy]

Hello I am little bit confused about one topic on theoretical Physics and that is If we want to describe our Quantum world (example atoms in metal) then should I use Quantum field theory or Quantum mechanics?

 

[A. Neumaier]

If you want to have enough detail, you need quantum field theory, but in many cases, quantum mechanics is sufficient. Metals can be described in both ways. Usually one begins with the particle description (quantum mechanics) and then switches to the field description (quantum field theory) as it is more powerful.

 

[AleksanderPhy]

If you want to have enough detail, you need quantum field theory, but in many cases, quantum mechanics is sufficient. Metals can be described in both ways. Usually one begins with the particle description (quantum mechanics) and then switches to the field description (quantum field theory) as it is more powerful.

Thanks for such great awnser!