Function expectation_value_kernel 

pub fn expectation_value_kernel(
    state: &HilbertState,
    operator: &Operator,
) -> Result<f64, PhysicsError>

Calculates the expectation value: $\langle A \rangle = \langle \psi | A | \psi \rangle$.

Arguments

• state - Quantum state $|\psi\rangle$.
• operator - Observable operator $A$.

Returns

• Ok(f64) - Expectation value (Real part of complex result).