POVMSampler

class POVMSampler(sampler: BaseSamplerV2)

Bases: object

A BaseSamplerV2-compatible interface for sampling POVMs.

This class does not implement the Sampler primitive interface as a subclass but rather takes an existing instance of a Sampler primitive as its input. In this way, it is trivial for the end-user to switch between simulated or hardware-executed POVM sampling jobs.

Here is a simple example to get you started:

>>> from povm_toolbox.library import ClassicalShadows
>>> from povm_toolbox.sampler import POVMSampler
>>> from qiskit.circuit import QuantumCircuit
>>> from qiskit.primitives import StatevectorSampler
>>> circ = QuantumCircuit(2)
>>> _ = circ.h(0)
>>> _ = circ.cx(0, 1)
>>> povm = ClassicalShadows(2, seed=42)
>>> sampler = StatevectorSampler(seed=42)
>>> povm_sampler = POVMSampler(sampler)
>>> job = povm_sampler.run([circ], povm=povm, shots=16)
>>> result = job.result()

Now, if you want to execute your experiments on real hardware, you can simply replace the StatevectorSampler above by a SamplerV2:

from qiskit_ibm_runtime import SamplerV2
sampler = SamplerV2(...)

Initialize the POVM Sampler.

Parameters:

sampler (BaseSamplerV2) – the BaseSamplerV2 that is used to collect the POVM samples.

Attributes

sampler

The BaseSamplerV2 that is used to collect the POVM samples.

Methods

run(pubs: Iterable[povm_toolbox.sampler.POVMSamplerPubLike], *, shots: int | None = None, povm: POVMImplementation | None = None, pass_manager: StagedPassManager | None = None) → POVMSamplerJob

Run and collect samples from each pub.

Parameters:

• pubs (Iterable[povm_toolbox.sampler.POVMSamplerPubLike]) – An iterable of POVMSamplerPubLike objects. For example, a list of circuits or tuples (circuit, parameter_values, shots, povm).

• shots (int | None) – The total number of shots to sample for each pub that does not specify its own shots. If None, the default number of shots of the sampler is used.

• povm (POVMImplementation | None) – A POVM implementation to sample from for each pub that does not specify it own POVM. If None, each pub has to specify its own POVM.

• pass_manager (StagedPassManager | None) – An optional transpilation pass manager. For each pub, after its circuit has been composed with the measurement circuit, the pass manager will be used to transpile the composed circuit.

Returns:

The POVM sampler job object.

Return type:

POVMSamplerJob