Quantum Information (qiskit.quantum_info)

Operators

Operator(data[, input_dims, output_dims])	Matrix operator class
Pauli([data, x, z, label])	N-qubit Pauli operator.
Clifford(data[, validate, copy])	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.
CNOTDihedral([data, num_qubits, validate])	An N-qubit operator from the CNOT-Dihedral group.
PauliList(data)	List of N-qubit Pauli operators.
PauliTable(data)	Symplectic representation of a list Pauli matrices.
StabilizerTable(data[, phase])	Symplectic representation of a list Stabilizer matrices.
pauli_basis(num_qubits[, weight, pauli_list])	Return the ordered PauliTable or PauliList for the n-qubit Pauli basis.

States

Statevector(data[, dims])	Statevector class
DensityMatrix(data[, dims])	DensityMatrix class
StabilizerState(data[, validate])	StabilizerState 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_pauli(num_qubits[, group_phase, seed])	Return a random Pauli.
random_clifford(num_qubits[, seed])	Return a random Clifford operator.
random_quantum_channel([input_dims, ...])	Return a random CPTP quantum channel.
random_cnotdihedral(num_qubits[, seed])	Return a random CNOTDihedral element.
random_pauli_table(num_qubits[, size, seed])	Return a random PauliTable.
random_pauli_list(num_qubits[, size, seed, ...])	Return a random PauliList.
random_stabilizer_table(num_qubits[, size, seed])	DEPRECATED: Return a random StabilizerTable.

Analysis

hellinger_distance(dist_p, dist_q)	Computes the Hellinger distance between two counts distributions.
hellinger_fidelity(dist_p, dist_q)	Computes the Hellinger fidelity between two counts distributions.

Synthesis

OneQubitEulerDecomposer([basis, use_dag])	A class for decomposing 1-qubit unitaries into Euler angle rotations.
TwoQubitBasisDecomposer(gate[, ...])	A class for decomposing 2-qubit unitaries into minimal number of uses of a 2-qubit basis gate.
two_qubit_cnot_decompose
Quaternion(data)	A class representing a Quaternion.
decompose_clifford(clifford[, method])	DEPRECATED: Decompose a Clifford operator into a QuantumCircuit.
XXDecomposer([euler_basis, embodiments, ...])	A class for optimal decomposition of 2-qubit unitaries into 2-qubit basis gates of XX type (i.e., each locally equivalent to CAN(alpha, 0, 0) for a possibly varying alpha).