PHYSICS · Multi-part · Fermi University Physics · Quantum Mechanics · Quantum Information & Technology · Quantum information theory and communication
Quantum Information and Technology, Ch Entropy and compression
Problem
A trapped-ion qubit is initialised imperfectly, leaving it with a Bloch vector of magnitude r=0.6 pointing along +Z, so its density operator is ρ=21(I+rZ).
((a)) Find the eigenvalues of ρ.
((b)) Compute the von Neumann entropy S(ρ) in bits.