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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_decomposeA 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.
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