Introduction to IBM Quantum primitives

Primitives were created to simplify the most common tasks for quantum computers: namely, sampling quantum states and calculating expectation values. The IBM Quantum primitives (Estimator and Sampler) are implementations of the Qiskit primitives base classes. They provide a more sophisticated implementation (for example, by including error mitigation) as a cloud-based service and are used to access IBM Quantum® hardware.

The newest IBM Quantum primitive, Executor (which is in beta), provides a lower-level interface that gives more visibility and control without sacrificing performance. Executor also exposes additional capabilities that Sampler does not offer, such as additional twirling groups and twirling for circuits with fractional gates. Refer to Migrate from Sampler to Executor for more information on whether to migrate to Executor.

Estimator

Computes the expectation values for one or more observables with respect to states prepared by quantum circuits. Has built-in error suppression and mitigation methods.

Estimator quickstart →

Sampler

Samples the output register from the execution of one or more quantum circuits.

Sampler quickstart →

Executor (beta)

Samples output registers from quantum circuit executions based on input directives and gives you full control and transparency over customizing error mitigation methods.

Executor quickstart →

Next steps

Recommendations

• Learn about the primitive base classes that the IBM Quantum primitives are based on.
• Review detailed Estimator, Sampler, or Executor examples.
• See the input and output details for Estimator, Executor, and Sampler.
• Practice with primitives by working through the Cost function lesson in IBM Quantum Learning.
• See the Estimator API reference, Sampler API reference, and Executor API reference.