Question

Entanglement fidelity for a single qubit?

Answer 1

The finished size of a charm pack once it is sewn into a quilt is 4-1/2 inches. Now decide what size you want to make your quilt. Let's say a little crib size. If you do a layout of 6 blocks across and 7 blocks down (6 x 7) it will take 42 squares and the size will be 27 x 31-1/2

Answer 2

So I have been working out problems from the book "Quantum Computing Explained" by David McMahon. On page 166 he defines "Entanglement Fidelity" and says the following: Consider a density operator for a single qubit that is diagonal with respect to the computational basis: ρ=f|0⟩⟨0|+(1−f)|1⟩⟨1|ρ=f|0⟩⟨0|+(1−f)|1⟩⟨1|. The parameter ff is known as the entanglement fidelity. For example, if ρ=(3/4)|0⟩⟨0|+(1/4)|1⟩⟨1|ρ=(3/4)|0⟩⟨0|+(1/4)|1⟩⟨1| ,then the entanglement fidelity is 3/4. I have a few questions regarding this:

A) What does entanglement fidelity mean? (especially in the case of a single qubit)

B) Since the trace of a density matrix should be 1, I understand that the parameter ff can range between 0 to 1. How should I interpret the various values of the parameter ff