Release Notes#

0.4.5#

Release 0.4.5 removes version pin qiskit<1.0 from setup.py. Otherwise there are no material changes.

Fixes a bug in solve_lmde_perturbation() in which the perturbation_labels argument was being unexpectedly re-ordered, leading to errors when retrieving results.

Qiskit Dynamics 0.4.3 is a minor maintenance release.

Qiskit Dynamics 0.4.2 is an incremental release with minor bug fixes and additional warnings to help guide users through issues.

The subsystem_labels option has been removed from the DynamicsBackend. This removal impacts some technical aspects of the backend returned by DynamicsBackend.from_backend() when the subsystem_list argument is used. Using the subsystem_list argument with DynamicsBackend.from_backend() restricts the internally constructed model to the qubits in subsystem_list. When doing so previously, the option subsystem_labels would be set to subsystem_labels, and subsystem_dims would record only the dimensions for the systems in subsystem_labels. To account for the fact that subsystem_labels no longer exists, DynamicsBackend.from_backend() now constructs subsystem_dims to list a dimension for all of the qubits in the original backend, however now the dimensions of the removed systems are given as 1 (i.e. they are treated as trivial quantum systems with a single state). This change is made only for technical bookkeping purposes, and has no impact on the core simulation behaviour.

In the case that envelope is a constant, the Signal.__init__() method has been updated to not attempt to evaluate carrier_freq == 0.0 if carrier_freq is a JAX tracer. In this case, it is not possible to determine if the Signal instance is constant. This resolves an error that was being raised during JAX tracing if carrier_freq is abstract.

Fixes bug in DynamicsBackend.run() that caused miscounting of the number of classical registers in a QuantumCircuit (issue #251).

DynamicsBackend.options.normalize_states now also controls whether or not the probability distribution over outcomes is normalized before sampling outcomes.

For users that have JAX installed, a warning has been added upon import of Qiskit Dynamics to notify the user of issues with certain versions: JAX versions newer than 0.4.6 break the perturbation module, and to use perturbation module with versions 0.4.4, 0.4.5, or 0.4.6, it is necessary to set os.environ['JAX_JIT_PJIT_API_MERGE'] = '0' before importing JAX or Dynamics.

A warning has been added to InstructionToSignals class when converting pulse schedules to signals to notify the user if the usage of SetFrequency or ShiftFrequency commands result in a digital carrier frequency larger than the Nyquist frequency of the envelope sample size dt.

Qiskit Dynamics 0.4.1 is an incremental release with minor bug fixes, documentation updates, and usability features.

The DynamicsBackend.from_backend() method has been updated to automatically populate the control_channel_map option based on the supplied backend if the user does not supply one.

Due to a bug in JAX, Dynamics can only be used with jax<=0.4.6. As they depend on newer versions of JAX, Dynamics is also now only compatible with diffrax<=0.3.1 and equinox<=0.10.3.

A bug in DynamicsBackend.__init__() causing existing measurement instructions for a user-supplied Target to be overwritten has been fixed.

Fixes a bug in the perturbation module with internal sorting of Multiset instances, which caused incorrect computation of perturbation theory terms when >10 perturbations are present.

The repository has been moved from [github.com/Qiskit/qiskit-dynamics](https://github.com/Qiskit/qiskit-dynamics) to [github.com/Qiskit-Extensions/qiskit-dynamics](https://github.com/Qiskit-Extensions/qiskit-dynamics), and the documentation has been moved from [qiskit.org/documentation/dynamics](https://qiskit.org/documentation/dynamics) to [qiskit.org/ecosystem/dynamics](https://qiskit.org/ecosystem/dynamics/).