qiskit.quantum_info.purity¶
-
purity(state, validate=True)[Quellcode]¶ Calculate the purity of a quantum state.
The purity of a density matrix \(\rho\) is
\[\text{Purity}(\rho) = Tr[\rho^2]\]- Parameter
state (Statevector or DensityMatrix) – a quantum state.
validate (bool) – check if input state is valid [Default: True]
- Rückgabe
the purity \(Tr[\rho^2]\).
- Rückgabetyp
float
- Verursacht
QiskitError – if the input isn’t a valid quantum state.