qiskit.quantum_info.entropy¶
-
entropy(state, base=2)[source]¶ Calculate the von-Neumann entropy of a quantum state.
The entropy \(S\) is given by
\[S(\rho) = - Tr[\rho \log(\rho)]\]- Parameters
state (Statevector or DensityMatrix) – a quantum state.
base (int) – the base of the logarithm [Default: 2].
- Returns
The von-Neumann entropy S(rho).
- Return type
float
- Raises
QiskitError – if the input state is not a valid QuantumState.