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TwirlingOptions

class TwirlingOptions(*args, **kwargs)

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Twirling options.

Attributes

enable_gates

Type: UnsetType | bool

Default value: Unset

Whether to apply 2-qubit Clifford gate twirling. Default: False.

enable_measure

Type: UnsetType | bool

Default value: Unset

Whether to enable twirling of measurements.

Twirling will only be applied to those measurement registers not involved within a conditional logic. Default: True for Estimator, false for Sampler.

num_randomizations

Type: UnsetType | int | Literal['auto']

Default value: Unset

The number of random samples to use when twirling or peforming sampled mitigation.

If num_randomizations is “auto”, for every pub executed shots times:

  • If shots_per_randomization is also “auto”, shots_per_randomization is set first as described below, then num_randomizations is set as ceil(shots/shots_per_randomization), where ceil is the ceiling function.
  • Otherwise, the value is set to ceil(shots/shots_per_randomization).

Default: “auto”.

Note

The shots value specified in a PUB or in the run() method is considered part of the primitive execution interface and therefore is always obeyed. default_shots, on the other hand, is considered a Qiskit Runtime specific option. Therefore, the product of num_randomizations and shots_per_randomization takes precedence over default_shots.

shots_per_randomization

Type: UnsetType | int | Literal['auto']

Default value: Unset

The number of shots to run for each random sample.

If “auto”, for every pub executed shots times:

  • If num_randomizations is also “auto”, the value is set to 64 for PEC mitigation or to max(64, ceil(shots / 32)) in all other cases, where ceil is the ceiling function.
  • Otherwise, the value is set to ceil(shots/num_randomizations).

Default: “auto”.

Note

The shots value specified in a PUB or in the run() method is considered part of the primitive execution interface and therefore is always obeyed. default_shots, on the other hand, is considered a Qiskit Runtime specific option. Therefore, the product of num_randomizations and shots_per_randomization takes precedence over default_shots.

strategy

Type: UnsetType | Literal['active', 'active-accum', 'active-circuit', 'all']

Default value: Unset

Specify the strategy of twirling qubits in identified layers of 2-qubit twirled gates.

Allowed values are:

  • If "active" only the instruction qubits in each individual twirled layer will be twirled.
  • If "active-circuit" the union of all instruction qubits in the circuit will be twirled in each twirled layer.
  • If "active-accum" the union of instructions qubits in the circuit up to the current twirled layer will be twirled in each individual twirled layer.
  • If "all" all qubits in the input circuit will be twirled in each twirled layer.

Default: “active-accum”.

Methods