Skip to main contentIBM Quantum Documentation
You are viewing the API reference for an old version of Qiskit SDK. Switch to latest version



Quantum Volume

qv_circuits(qubit_lists[, ntrials, qr, cr, seed])Return a list of square quantum volume circuits (depth=width)
QVFitter([backend_result, …])Class for fitters for quantum volume.

Randomized Benchmarking

Randomization benchmarking (RB) is a well-known technique to measure average gate performance by running sequences of random Clifford gates that should return the qubits to the initial state. Qiskit Ignis has tools to generate one- and two-qubit gate Clifford RB sequences simultaneously, as well as performing interleaved RB, purity RB and RB on the non-Clifford CNOT-Dihedral group.

randomized_benchmarking_seq([nseeds, …])Generate generic randomized benchmarking (RB) sequences.
RBFitter(backend_result, cliff_lengths[, …])Class for fitters for randomized benchmarking.
InterleavedRBFitter(original_result, …[, …])Class for fitters for interleaved RB, derived from RBFitterBase class.
PurityRBFitter(purity_result, npurity, …)Class for fitter for purity RB.
CNOTDihedralRBFitter(cnotdihedral_Z_result, …)Class for fitters for non-Clifford CNOT-Dihedral RB.
CNOTDihedral(data[, validate])CNOT-dihedral Object Class.
count_gates(qobj, basis, qubits)Take a compiled qobj and output the number of gates in each circuit.
gates_per_clifford(transpiled_circuits_list, …)Take a list of transpiled QuantumCircuit and use these to calculate the number of gates per Clifford.
calculate_1q_epg(gate_per_cliff, epc_1q, qubit)Convert error per Clifford (EPC) into error per gates (EPGs) of single qubit basis gates.
calculate_2q_epg(gate_per_cliff, epc_2q, …)Convert error per Clifford (EPC) into error per gate (EPG) of two qubit cx gates.
calculate_1q_epc(gate_per_cliff, epg_1q, qubit)Convert error per gate (EPG) into error per Clifford (EPC) of single qubit basis gates.
calculate_2q_epc(gate_per_cliff, epg_2q, …)Convert error per gate (EPG) into error per Clifford (EPC) of two qubit cx gates.
coherence_limit([nQ, T1_list, T2_list, gatelen])The error per gate (1-average_gate_fidelity) given by the T1,T2 limit.
twoQ_clifford_error(ngates, gate_qubit, gate_err)The two qubit Clifford gate error given measured errors in the primitive gates used to construct the Clifford (see arxiv:1712.06550).


state_tomography_circuits(circuit, …[, …])Return a list of quantum state tomography circuits.
process_tomography_circuits(circuit, …[, …])Return a list of quantum process tomography circuits.
gateset_tomography_circuits([…])Return a list of quantum gate set tomography (GST) circuits.
basisQuantum tomography basis
StateTomographyFitter(result, circuits[, …])Maximum-Likelihood estimation state tomography fitter.
ProcessTomographyFitter(result, circuits[, …])Maximum-Likelihood estimation process tomography fitter.
GatesetTomographyFitter(result, circuits[, …])Initialize gateset tomography fitter with experimental data.
TomographyFitter(result, circuits[, …])Base maximum-likelihood estimate tomography fitter class
marginal_counts(counts[, meas_qubits, pad_zeros])Compute marginal counts from a counts dictionary.
combine_counts(counts1, counts2)Combine two counts dictionaries.
expectation_counts(counts)Converts count dict to an expectation counts dict.
count_keys(num_qubits)Return ordered count keys.


BConfig(backend[, indicator])This class is used to create a GHZ circuit with parallellized CNOT gates to increase fidelity
get_ghz_simple(n[, measure, full_measurement])Creates a linear GHZ state with the option of measurement
get_ghz_mqc(n, delta[, full_measurement])This function creates an MQC circuit with n qubits, where the middle phase rotation around the z axis is by delta
get_ghz_mqc_para(n[, full_measurement])This function creates an MQC circuit with n qubits, where the middle phase rotation around the z axis is parameterized
get_ghz_po(n, delta)This function creates an Parity Oscillation circuit with n qubits, where the middle superposition rotation around the x and y axes is by delta
get_ghz_po_para(n)This function creates a Parity Oscillation circuit with n qubits, where the middle superposition rotation around
ordered_list_generator(counts_dictionary, qn)For parity oscillations; just arranges dictionary of counts in bitwise binary order to compute dot products more easily
composite_pauli_z(qn)Generates n tensored pauli z matrix upon input of qubit number
composite_pauli_z_expvalue(counts_dictionary, qn)Generates expectation value of n tensored pauli matrix upon input of qubit number and composite pauli matrix
Plotter(label)Various plots of the ground state in MQC and PO experiments
rho_to_fidelity(rho)Get fidelity given rho :type rho: float :param rho: The density matrix

Topological Codes

RepetitionCode(d[, T])Implementation of a distance d repetition code, implemented over T syndrome measurement rounds.
GraphDecoder(code[, S])Class to construct the graph corresponding to the possible syndromes of a quantum error correction code, and then run suitable decoders.
lookuptable_decoding(training_results, …)Calculates the logical error probability using postselection decoding.
postselection_decoding(results)Calculates the logical error probability using postselection decoding.


AccreditationCircuits(target_circ[, …])This class generates accreditation circuits from a target.
AccreditationFitter()Class for fitters for accreditation
QOTP(circ, num[, two_qubit_gate, …])Performs a QOTP (or random compilation) on a generic circuit.
QOTPCorrectCounts(qotp_counts, qotp_postp)Corrects a dictionary of results, shifting the qotp
Was this page helpful?
Report a bug or request content on GitHub.