Exploring Quantum Measurements and Unitary Operators

[Heidi]

Hi Pfs

I read this answer in
https://quantumcomputing.stackexcha...-gates-must-be-unitary-what-about-measurement

Quantum measurements are special cases of quantum channels (CPTP cards). Stinespring dilation states that any quantum channel is realized by partially tracing a unitary operator acting on a possibly larger Hilbert space.

I wonder if it is true. and in this case is it possible to give an example of such unitary operator? i suppose that the evolution process is random.

[I translated the French part. Please use English only.]

 

[Heidi]

I found this (in the same forum)
https://quantumcomputing.stackexcha...ng-dilation-of-t-otimes-i-for-some-cptp-map-t
But i am unable to understand if it is an answer to my question!