This node calculates the expectation value of any operator with regard to an arbitrary state.
For an operator $\hat{O}$ and a state $\psi$, this node calculates $\langle \psi | \hat{O} | \psi \rangle$.
The node has the following inputs:
The node displays the expectation value of the operator.
In the example below, the expectation value of the position operator is calculated with regard to a non-stationary state and displayed in the node.