qml.qinfo

Overview

This module provides a collection of methods to return quantum information quantities from QNode returning state().

Transforms

QNode transforms for the quantum information quantities.

Functions

classical_fisher(qnode[, argnums])

Returns a function that computes the classical fisher information matrix (CFIM) of a given QNode or quantum tape.

fidelity(qnode0, qnode1, wires0, wires1)

Compute the fidelity for two QNode returning a state() (a state can be a state vector or a density matrix, depending on the device) acting on quantum systems with the same size.

mutual_info(qnode, wires0, wires1[, base])

Compute the mutual information from a QNode returning a state():

quantum_fisher(qnode, *args, **kwargs)

Returns a function that computes the quantum fisher information matrix (QFIM) of a given QNode.

reduced_dm(qnode, wires)

Compute the reduced density matrix from a QNode returning state().

vn_entropy(qnode, wires[, base])

Compute the Von Neumann entropy from a QNode returning a state().