To get a distribution of some dynamic variable of a wavefunction, we actually need to prepare an ensemble of particles, in which all the particles have the same wavefunction, right?(adsbygoogle = window.adsbygoogle || []).push({});

And no-cloning theorem states that it's impossible to copy an unknown quantum state.

So is this a contradiction？

I've figured that in order to prepare an ensemble we have to know the wavefunction, so it doesn't really fit the situation under which the no-cloning theorem applies. But I can't really give myself a clear and detailed reasoning to convince myself. Could you guys help me explain it?

**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!

# Confusion about preparing ensemble of particles and no-cloning theorem

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