qiskit.quantum_info.mutual_information

mutual_information(state, base=2)

Calculate the mutual information of a bipartite state.

The mutual information $I$ is given by:

where $\rho_A=Tr_B[\rho_{AB}], \rho_B=Tr_A[\rho_{AB}]$, are the reduced density matrices of the bipartite state $\rho_{AB}$.

Parameters

• state (Statevector orDensityMatrix) – a bipartite state.
• base (int) – the base of the logarithm [Default: 2].

Returns

The mutual information $I(\rho_{AB})$.

Return type

float

Raises

• QiskitError – if the input state is not a valid QuantumState.
• QiskitError – if input is not a bipartite QuantumState.