kraus

qujax.kraus(densitytensor, arrays, qubit_inds)

Performs Kraus operation.

\[\rho_\text{out} = \sum_i B_i \rho_\text{in} B_i^{\dagger}\]

Parameters:

• densitytensor (ndarray) – Input density matrix of shape=(2, 2, …) and ndim=2*n_qubits

• arrays (Iterable[ndarray]) – Sequence of arrays containing the Kraus operators (in tensor form).

• qubit_inds (Sequence[int]) – Sequence of qubit indices on which to apply the Kraus operation.

Returns:

Updated density matrix.

Return type:

ndarray