#technologynew

IBM unveils Qiskit SDK v2.0. In addition to improving speed, the second major version release lays the groundwork for additional tools and features in the coming months.

Qiskit release lifecycle summary

IBM will discuss Qiskit SDK v2.0's intriguing new features below. Qiskit SDK v2.0 may be more concerned with removing the old than introducing the new.

The Qiskit SDK adopted Semantic Versioning last year with the release of its first major version. This technique classifies releases as major, minor, and patch versions using the format. Significant version releases feature incompatible Application Programming Interface changes. In this transition, it committed to 18-month support cycles. Qiskit will preserve each major version for six months after its replacement is released, therefore a major version is only provided once a year and contains only breaking changes.

Best New Features & Enhancements

This page will cover the most important updates:

A new C API

A C-language API for SparseObservable is introduced in this major version. This new capability is only the start of a robust C interface for the Qiskit SDK; expect considerable extensions in the remaining v2.x series. Work is expected to aid the quest for quantum advantage and large-scale quantum experiments.

Removing obsolete features

Many minor versions in the v1.x series have deprecation warnings to help us improve the SDK. This major version removes all deprecated classes, functions, and modules.

Continuous performance improvements

Porting additional Qiskit SDK functionality to Rust has resulted in a 2x speedup for circuit construction benchmarking and a 20% speedup for translation benchmarking.

Introducing boxes and stretches

For future changes to dynamic circuits on IBM QPUs, Qiskit SDK v2.0 gives more circuit structure possibilities.

Revolutionising Change

Qiskit SDK v2.0 eliminates all deprecations IBM has indicated since v1.0 owing to its importance.

This is essential to the new, more stable release cycle introduced with Qiskit SDK v1.0 last year. Because of this, breaking changes only occur once a year, giving you adequate time to prepare with deprecation warnings in minor version releases. IBM will describe some of the key changes below, but the full release notes and migration guide provide the entire list of breaking changes and how to modify your projects.

First, some Qiskit SDK components were removed. The modules are qiskit.pulse, qobj, and assembler. The qobj and assembler modules were closely linked to the REST API specification for the previous IBM Quantum Experience, which was the forerunner of the current IBM Quantum Platform, and are now legacy paths, so their removal is part of transpiler interface cleanup.

Since they were based on IBM Quantum Experience, BackendV1, ProviderV1, and all associated models and utilities were removed from Qiskit SDK v2.0. This means all qiskit.providers.models objects and fake backend classes based on BackendV1 in fake_provider have been removed.

Primitive V1 implementations and aliases have been replaced with V2 ones. Remember that only Primitive V1 implementations, not definitions, were deleted. This elimination includes these classes:

Estimator prefers StatevectorEstimatorV2.

Sampler for V2 equivalent, StatevectorSampler

In favour of BackendEstimatorV2.

BackendSamplerV2 instead of BackendSampler

BaseEstimatorV1 was aliased.

BaseV1 was aliased as BaseSampler.

Eliminating Qiskit Pulse

One of the biggest changes to Qiskit SDK v2.0 is the removal of the pulse module. This is part of IBM Quantum QPUs' attempts to provide higher-level services for utility-scale experimentation and quantum advantage after removing Pulse-level control.