Quantum Information (qiskit.quantum_info)

Operators

Operator(data[, input_dims, output_dims])	Matrix operator class
Clifford(data[, validate])	An N-qubit unitary operator from the Clifford group.
ScalarOp(dims[, coeff])	Scalar identity operator class.
SparsePauliOp(data[, coeffs])	Sparse N-qubit operator in a Pauli basis representation.
Pauli([z, x, label])	A simple class representing Pauli Operators.
pauli_group(number_of_qubits[, case])	Return the Pauli group with 4^n elements.
Quaternion(data)	A class representing a Quaternion.
PauliTable(data)	Symplectic representation of a list Pauli matrices.
StabilizerTable(data[, phase])	Symplectic representation of a list Stabilizer matrices.
pauli_basis(num_qubits[, weight])	Return the ordered PauliTable for the n-qubit Pauli basis.

States

Statevector(data[, dims])	Statevector class
DensityMatrix(data[, dims])	DensityMatrix class

Channels

Choi(data[, input_dims, output_dims])	Choi-matrix representation of a Quantum Channel.
SuperOp(data[, input_dims, output_dims])	Superoperator representation of a quantum channel.
Kraus(data[, input_dims, output_dims])	Kraus representation of a quantum channel.
Stinespring(data[, input_dims, output_dims])	Stinespring representation of a quantum channel.
Chi(data[, input_dims, output_dims])	Pauli basis Chi-matrix representation of a quantum channel.
PTM(data[, input_dims, output_dims])	Pauli Transfer Matrix (PTM) representation of a Quantum Channel.

Measures

average_gate_fidelity(channel[, target, …])	Return the average gate fidelity of a noisy quantum channel.
process_fidelity(channel[, target, …])	Return the process fidelity of a noisy quantum channel.
gate_error(channel[, target, require_cp, …])	Return the gate error of a noisy quantum channel.
diamond_norm(choi, **kwargs)	Return the diamond norm of the input quantum channel object.
state_fidelity(state1, state2[, validate])	Return the state fidelity between two quantum states.
purity(state[, validate])	Calculate the purity of a quantum state.
concurrence(state)	Calculate the concurrence of a quantum state.
entropy(state[, base])	Calculate the von-Neumann entropy of a quantum state.
entanglement_of_formation(state)	Calculate the entanglement of formation of quantum state.
mutual_information(state[, base])	Calculate the mutual information of a bipartite state.

Utility Functions

partial_trace(state, qargs)	Return reduced density matrix by tracing out part of quantum state.
shannon_entropy(pvec[, base])	Compute the Shannon entropy of a probability vector.

Random

random_statevector(dims[, seed])	Generator a random Statevector.
random_density_matrix(dims[, rank, method, seed])	Generator a random DensityMatrix.
random_unitary(dims[, seed])	Return a random unitary Operator.
random_hermitian(dims[, traceless, seed])	Return a random hermitian Operator.
random_clifford(num_qubits[, seed])	Return a random Clifford operator.
random_quantum_channel([input_dims, …])	Return a random CPTP quantum channel.
random_pauli_table(num_qubits[, size, seed])	Return a random PauliTable.
random_stabilizer_table(num_qubits[, size, seed])	Return a random StabilizerTable.
random_state(dim[, seed])	DEPRECATED Return a random quantum state.

Analysis

hellinger_fidelity(dist_p, dist_q)

Computes the Hellinger fidelity between two counts distributions.

Synthesis

OneQubitEulerDecomposer([basis])	A class for decomposing 1-qubit unitaries into Euler angle rotations.
TwoQubitBasisDecomposer(gate[, basis_fidelity])	A class for decomposing 2-qubit unitaries into minimal number of uses of a 2-qubit basis gate.
two_qubit_cnot_decompose	A class for decomposing 2-qubit unitaries into minimal number of uses of a 2-qubit basis gate.
euler_angles_1q(unitary_matrix)	DEPRECATED: Compute Euler angles for a single-qubit gate.