basic_device_gate_errors(properties=None, gate_error=True, thermal_relaxation=True, gate_lengths=None, gate_length_units='ns', temperature=0, warnings=None, target=None)[source]#

Return QuantumErrors derived from either of a devices BackendProperties or Target.

If non-default values are used gate_lengths should be a list of tuples (name, qubits, value) where name is the gate name string, qubits is either a list of qubits or None to apply gate time to this gate one any set of qubits, and value is the gate time in nanoseconds.

The resulting errors may contains two types of errors: gate errors and relaxation errors. The gate errors are generated only for Gate objects while the relaxation errors are generated for all Instruction objects. Exceptionally, no QuantumError s are generated for Measure since ReadoutError s are generated separately instead.

  • properties (BackendProperties) – device backend properties.

  • gate_error (bool) – Include depolarizing gate errors (Default: True).

  • thermal_relaxation (Bool) – Include thermal relaxation errors (Default: True). If no t1 and t2 values are provided (i.e. None) in target for a qubit, an identity QuantumError` (i.e. effectively no thermal relaxation error) will be added to the qubit even if this flag is set to True. If no ``frequency is not defined (i.e. None) in target for a qubit, no excitation is considered in the thermal relaxation error on the qubit even with non-zero temperature.

  • gate_lengths (list) – Override device gate times with custom values. If None use gate times from backend properties. (Default: None).

  • gate_length_units (str) – Time units for gate length values in gate_lengths. Can be ‘ns’, ‘ms’, ‘us’, or ‘s’ (Default: ‘ns’).

  • temperature (double) – qubit temperature in milli-Kelvin (mK) (Default: 0).

  • warnings (bool) – DEPRECATED, Display warnings (Default: None).

  • target (Target) – device backend target (Default: None). When this is supplied, several options are disabled: properties, gate_lengths and gate_length_units are not used during the construction of gate errors. Default values are always used for warnings.


A list of tuples (label, qubits, QuantumError), for gates with non-zero quantum error terms, where label is the label of the noisy gate, qubits is the list of qubits for the gate.

Return type:



NoiseError – If invalid arguments are supplied.