Chapter 3

Question 1

What properties must a projector satisfy?

Answer 1

1. Hermiticity
2. Idempotency (it equals its own square)

Question 2

What does applying a projector to a vector do?

Answer 2

Finds the component of the vector in the subspace defined by the projector

Question 3

How do you perform a projective measurement?

Answer 3

1. Define a set of projectors which sum to 1
2. ⟨ψ|Πk|ψ⟩

Question 4

How is the CHSH qunatity defined?

Answer 4

S = A0B0 + A0B1 + A1B0 − A1B

Question 5

What is the CHSH inequality?

Answer 5

⟨S⟩ | ≤ 2