Quantum Algorithms, Quantum Computing, Physics, Mathematics, Education.
But, when calculating ⟨ZI⟩, we take the eigenvalue of the qubit corresponding to the identity operator to always be +1. That’s why |11⟩ is subtracted in the equation for ⟨ZI⟩. The procedure above can be easily extended to any number of qubits, and, given the measurement results for the 3^n Pauli