Changelog

Fixed

• Fixed a bug where nonequal boxes were considered equal (#14716) (#14722)
• Restore correct max_trials behaviour for VF2Layout pass (#14667) (#14692)
• Add missing stacklevel to deprecation warning for 3.9 (#14651) (#14658)
• fixing MCXSynthesis1DirtyKG24 and MCXSynthesis2DirtyKG24 plugins (#14670) (#14671)
• Use Arc instead of Box for internal expression nodes in SymbolExpr (#14660) (#14665)

Release notes: https://docs.quantum.ibm.com/api/qiskit/release-notes/2.1#210

Changelog

Deprecated

• Deprecate Python 3.9 support (#14543)
• Move PendingDeprecations to Deprecations in the circuit library (#13604)

Added

• Support stretchy delays in box (#13899)
• Annotation serialisation framework (#14439)
• Introduce PauliLindbladMap (#14383)
• Initial Target C API (#14248)
• Oxidize the Solovay Kitaev algorithm (#14203)
• Context-aware dynamical decoupling (#12825)
• added get_qpy_version to retrieve qpy version (#14212)
• Added support for querying version information in the Qiskit C API. (#14423)
• Add QubitSparsePauli and QubitSparsePauliList classes to quantum_info (#14283)
• Change style of DAG generated in dag_drawer() (#13253)
• Add method has_control_flow_op() to QuantumCircuit (#13936)
• Directly expose QkComplex64 to the C API (#14340)
• Simpler definitions for standard gates (#14180)
• Clifford unitary synthesis plugin (#14429)
• CliffordT optimization (#14433)
• Implementation of a Limited QASM3 Exporter except controlflow and Classical Variables in Rust (#14226)
• block diagonal optimized quantum shannon decomposition (#13688)
• Clifford+T transpiler pipeline (#14225)
• New methods in ObservablesArray: sparse_observables_array and sparse_observables_array_slice (#14344)
• Added VF2PostLayout at the end of optimization stage for level 3 (#14120)
• Visualize boxes with disjoint vertical spans in parallel (#14386)
• Add ParameterExpression in Rust (#13278)
• Add C API function to add a delay (#14347)
• C-API: Add fix for Windows and C++ (#14273)
• Ancilla-Free Quantum Adder with Sublinear Depth (#13975)
• Wrote ObservablesArray.apply_layout and some additional methods (#14289)
• Add initial C API for circuit construction (#14006)
• Unify identifer handling of Var and Stretch in DAGCircuit (#14000)
• Add random circuit with graph (#12474)
• HLS plugin for new MCX Decompositions (#14143)
• Improve annotated plugin (#13916)
• Make PrimitiveJob serializable (#12963)
• Better MCX Decomposition with logarithmic Toffoli Depth (#13922)
• Better synthesis for multi-controlled U1Gate (#14061)
• Update CS and CSdg in the equivalence library (#14001)

Changed

• Remove sympy as a hard dependency (#14396)
• Improve Sabre heuristic defaults (#14458)
• Remove symengine from the requirements list (#14389)
• Remove dateutil as a requirement (#14395)
• Do not construct layout passes with no coupling map (#14353)

Fixed

• Fix sympify() for expressions with vector element .subs() (#14641) (#14642)
• Extending rustiq synthesis plugin to work SparseObservables (#14582) (#14628)
• Fix classical bit mapping in HLS pass (#14597) (#14625)
• Fix ElidePermutations pass in the presence of PermutationGates (#14603) (#14623)
• Fix ApplyLayout with empty layout (#14606) (#14613)
• Fix random number generator seed argument for quantum_volume (#14586) (#14592)
• allows string values in assign_parameters with strict=False (#14365) (#14554)
• Fix HLS preserve order (#14539)
• Fix parameter deserialization bugs in QPY (#13727)
• Reduce space inside BoxOps and fix layering issues with boxes (#14529)
• Oxidize the Solovay Kitaev algorithm (#14203)
• Fix Sabre rebuild with nested Var and Stretch (#14488)
• Fixed AND terms for OR in quantum_or.py (#14436)
• Fix ConsolidateBlocks pass for collecting non-CX KAK gate (#14417)
• Fix construction of IQP circuits (#14363)
• Bug fix in HighLevelSynthesis fast-return mechanism (#14349)
• Fix UnitarySynthesis to respect synth_gates (#14345)
• C-API: Add fix for Windows and C++ (#14273)
• Fix alignment checks of stretch variables (#14330)
• Fix incorrect error estimation in VF2 fallback (#14218)
• Fix caching logic in SolovayKitaevSynthesis plugin (#14304)
• Bug fixes in Solovay Kitaev Decomposition (#14217)
• Fix display of Box End after transpile in text drawer (#14278)
• Fix pickle and repr for Duration. (#14174)
• Fix circuit-metadata propagation in SabreLayout (#14186)
• use XXPlusYYGate in excitation_preserving (#14128)
• Fix qpy for MCMTGate (#14096) (#14118)
• Fix qpy for MCMTGate (#14096)
• Consistent sparse list format in sparse operators (#14067) (#14110)
• Consistent sparse list format in sparse operators (#14067)
• Minor fixes/improvements to some MCX synthesis methods (#14093)
• Fix ignored errors/durations in generate_preset_pass_manager if dt is set (#14065) (#14098)
• Fix ignored errors/durations in generate_preset_pass_manager if dt is set (#14065)
• Fix global phase update in BasisTranslator Pass (backport #14078) (#14092)
• Fix global phase update in BasisTranslator Pass (#14078)
• Fixes to various graphs in the docs (#14055) (#14076)
• Fixes to various graphs in the docs (#14055)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (backport #14041) (#14044)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (#14041)
• Introduce custom sympy srepr parser (#14024)
• Introduce custom sympy srepr parser [stable/2.0] (#14023)
• Preserve bit locations through pickle (backport #13980) (#14011)
• Preserve bit locations through pickle (#13980)
• Fix string and standard gate mismatch in commutation checker (backport #13991) (#14004)
• Fix string and standard gate mismatch in commutation checker (#13991)

Changelog

Fixed

• Fix classical bit mapping in HLS pass (#14597) (#14624)
• Fix ElidePermutations pass in the presence of PermutationGates (#14603) (#14621)
• Fix ApplyLayout with empty layout (#14606) (#14616)
• Fix random number generator seed argument for quantum_volume (#14586) (#14591)
• Avoid using rustworkx 0.16.0 methods in vf2_utils (backport #14513) (#14534)
• Fix HLS preserve order (#14539) (#14540)
• Fix Sabre rebuild with nested Var and Stretch (#14488) (#14494)

Changelog

Deprecated

• Deprecate Python 3.9 support (#14543)
• Move PendingDeprecations to Deprecations in the circuit library (#13604)

Added

• Support stretchy delays in box (#13899)
• Annotation serialisation framework (#14439)
• Introduce PauliLindbladMap (#14383)
• Initial Target C API (#14248)
• Oxidize the Solovay Kitaev algorithm (#14203)
• Context-aware dynamical decoupling (#12825)
• added get_qpy_version to retrieve qpy version (#14212)
• Added support for querying version information in the Qiskit C API. (#14423)
• Add QubitSparsePauli and QubitSparsePauliList classes to quantum_info (#14283)
• Change style of DAG generated in dag_drawer() (#13253)
• Add method has_control_flow_op() to QuantumCircuit (#13936)
• Directly expose QkComplex64 to the C API (#14340)
• Simpler definitions for standard gates (#14180)
• Clifford unitary synthesis plugin (#14429)
• CliffordT optimization (#14433)
• Implementation of a Limited QASM3 Exporter except controlflow and Classical Variables in Rust (#14226)
• block diagonal optimized quantum shannon decomposition (#13688)
• Clifford+T transpiler pipeline (#14225)
• New methods in ObservablesArray: sparse_observables_array and sparse_observables_array_slice (#14344)
• Added VF2PostLayout at the end of optimization stage for level 3 (#14120)
• Visualize boxes with disjoint vertical spans in parallel (#14386)
• Add ParameterExpression in Rust (#13278)
• Add C API function to add a delay (#14347)
• C-API: Add fix for Windows and C++ (#14273)
• Ancilla-Free Quantum Adder with Sublinear Depth (#13975)
• Wrote ObservablesArray.apply_layout and some additional methods (#14289)
• Add initial C API for circuit construction (#14006)
• Unify identifer handling of Var and Stretch in DAGCircuit (#14000)
• Add random circuit with graph (#12474)
• HLS plugin for new MCX Decompositions (#14143)
• Improve annotated plugin (#13916)
• Make PrimitiveJob serializable (#12963)
• Better MCX Decomposition with logarithmic Toffoli Depth (#13922)
• Better synthesis for multi-controlled U1Gate (#14061)
• Update CS and CSdg in the equivalence library (#14001)

Changed

• Remove sympy as a hard dependency (#14396)
• Improve Sabre heuristic defaults (#14458)
• Remove symengine from the requirements list (#14389)
• Remove dateutil as a requirement (#14395)
• Do not construct layout passes with no coupling map (#14353)

Fixed

• Fix HLS preserve order (#14539)
• Fix parameter deserialization bugs in QPY (#13727)
• Reduce space inside BoxOps and fix layering issues with boxes (#14529)
• Oxidize the Solovay Kitaev algorithm (#14203)
• Fix Sabre rebuild with nested Var and Stretch (#14488)
• Fixed AND terms for OR in quantum_or.py (#14436)
• Fix ConsolidateBlocks pass for collecting non-CX KAK gate (#14417)
• Fix construction of IQP circuits (#14363)
• Bug fix in HighLevelSynthesis fast-return mechanism (#14349)
• Fix UnitarySynthesis to respect synth_gates (#14345)
• C-API: Add fix for Windows and C++ (#14273)
• Fix alignment checks of stretch variables (#14330)
• Fix incorrect error estimation in VF2 fallback (#14218)
• Fix caching logic in SolovayKitaevSynthesis plugin (#14304)
• Bug fixes in Solovay Kitaev Decomposition (#14217)
• Fix display of Box End after transpile in text drawer (#14278)
• Fix pickle and repr for Duration. (#14174)
• Fix circuit-metadata propagation in SabreLayout (#14186)
• use XXPlusYYGate in excitation_preserving (#14128)
• Fix qpy for MCMTGate (#14096) (#14118)
• Fix qpy for MCMTGate (#14096)
• Consistent sparse list format in sparse operators (#14067) (#14110)
• Consistent sparse list format in sparse operators (#14067)
• Minor fixes/improvements to some MCX synthesis methods (#14093)
• Fix ignored errors/durations in generate_preset_pass_manager if dt is set (#14065) (#14098)
• Fix ignored errors/durations in generate_preset_pass_manager if dt is set (#14065)
• Fix global phase update in BasisTranslator Pass (backport #14078) (#14092)
• Fix global phase update in BasisTranslator Pass (#14078)
• Fixes to various graphs in the docs (#14055) (#14076)
• Fixes to various graphs in the docs (#14055)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (backport #14041) (#14044)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (#14041)
• Introduce custom sympy srepr parser (#14024)
• Introduce custom sympy srepr parser [stable/2.0] (#14023)
• Preserve bit locations through pickle (backport #13980) (#14011)
• Preserve bit locations through pickle (#13980)
• Fix string and standard gate mismatch in commutation checker (backport #13991) (#14004)
• Fix string and standard gate mismatch in commutation checker (#13991)

Changelog

Fixed

• Fixed AND terms for OR in quantum_or.py (#14436) (#14462)
• Fix more spurious complex parts in circuit functions (#14431)
• Fix ConsolidateBlocks pass for collecting non-CX KAK gate (#14417) (#14424)

Changelog

Fixed

• Fix construction of IQP circuits (backport #14363) (#14373)
• Fix UnitarySynthesis to respect synth_gates (backport #14345) (#14351)
• Bug fix in HighLevelSynthesis fast-return mechanism (#14349) (#14358)
• Fix alignment checks of stretch variables (backport #14330) (#14331)
• Bug fixes in Solovay Kitaev Decomposition (#14217) (#14295)
• Fix incorrect error estimation in VF2 fallback (#14218) (#14316)
• Fix caching logic in SolovayKitaevSynthesis plugin (#14304) (#14311)
• Fix display of Box End after transpile in text drawer (#14278) (#14282)
• Fix pickle and repr for Duration. (backport #14174) (#14193)
• Fix circuit-metadata propagation in SabreLayout (#14186) (#14189)

Changelog

Fixed

• Bug fixes in Solovay Kitaev Decomposition (backport #14217) (#14294)
• Fix qpy for MCMTGate (#14096) (#14325)
• Fix incorrect error estimation in VF2 fallback (#14218) (#14315)
• Fix caching logic in SolovayKitaevSynthesis plugin (#14304) (#14312)
• Fix circuit-metadata propagation in SabreLayout (backport #14186) (#14190)
• Fix handling of custom gates named unitary in Split2qUnitaries (#14108)
• Fix global phase update in BasisTranslator Pass (backport #14078) (#14091)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (backport #14041) (#14043)

Release notes: https://docs.quantum.ibm.com/api/qiskit/release-notes/2.0

Changelog

Deprecated

• Extend deprecation of QuantumCircuit.duration and DAGCircuit.duration (#13960)
• Address BackendV1 deprecation warning oversights (#13868)
• The unused parameter dag in DAGNode constructor is deprecated (#13862)
• Deprecate convert_to_target (#12915)
• Deprecate qiskit.circuit.classicalfunction (#13786)
• Deprecate use of BackendProperties (BackendV1) in transpilation pipeline (#13719)
• Deprecate NormalizeRXAngle and rzx_templates (#13883)
• raise DeprecationWarning for a targetless timeline drawer (#13601)
• Deprecate atomic_evolution (#13603)
• Deprecation of MCMT in favor of MCMTGate (backport #13584) (#13810)
• Deprecate subclassing of Register and Bit (#13841)
• Deprecate BackendV2Converter (#12840)
• Deprecation of MCMT in favor of MCMTGate (#13584)
• Ensure translation stage always outputs ISA circuits (#13792)
• Deprecate BasicSimulator.run_experiment (#13750)
• Deprecate DAGNode.sort_key attribute (#13744)
• Deprecate show_idle and show_barrier in favor of idle_wires and plot_barriers (#13602)

Added

• The parameter idle_wires default flipped to False in all circuit drawers (#13865)
• [Stretch] Add stretch variable support to QuantumCircuit. (#13852)
• Delegate BasePass.__call__ to PassManager.run (#13820)
• Add representation of box (#13869)
• Use average gate fidelity in the commutation checker (#13874)
• [Stretch] Add +, -, *, / operators for classical expressions. (#13850)
• SparseObservable evolution (#13836)
• Port HighLevelSynthesis pass to rust (#13813)
• Light Cone Transpiler Pass (#12814)
• Add SparseObservable.compose (#13766)
• [Stretch] Support Float type in classical expressions. (#13832)
• C API for SparseObservable (#13694)
• [Stretch] Support const classical expressions. (#13811)
• Refactor parallelism utilities for public API (#12412)
• Single-register arithmetic gates (#13371)
• Add ContractIdleWiresInControlFlow optimisation pass (#13779)
• Promote linux aarch64 to tier 1 support (#13737)
• Remove dependance of BooleanExpression on tweedledum (#13769)
• Add default routing stage plugin (#13802)
• Add method to compute estimated duration of scheduled circuit (backport #13783) (#13881)
• Add method to compute estimated duration of scheduled circuit (#13783)
• Add dt to GenericBackendV2 (#13830)
• Better decomposition for multi-controlled 1-qubit gates (#13801)
• Add 2q fractional gates to the UnitarySynthesis transpiler pass (#13568)
• Add default translation stage plugin (#13794)
• Support SparseObservable to SparsePauliOp conversions (#13758)
• Add QuantumCircuit.noop for instructionless qubit use (#13774)
• Add new get_control_flow_name_mapping function (#13472)
• Add option max_block_width to CollectLinearFunctions and CollectClifford passes (#13661)
• feat: add method to convert BitArray into boolean array (#13653)
• Add option collect_from_back to CollectMultiQBlocks (#13612)
• StabilizerState.expectation_value can also accept SparsePauliOp (#13539)
• Quantum Multiplexer Simplification (#13099)

Changed

• The parameter idle_wires default flipped to False in all circuit drawers (#13865)
• Delegate BasePass.__call__ to PassManager.run (#13820)
• Use average gate fidelity in the commutation checker (#13874)
• Handle an optional symengine and sympy in qpy (#13917)
• Port HighLevelSynthesis pass to rust (#13813)
• New atomic_evolution signature in ProductFormula subclasses (#13918)
• Simplify return type of DAGCircuit::control_flow_op_nodes (#13892)
• Remove condition/c_if, duration, and unit from instructions (#13506)
• Add default routing stage plugin (#13802)
• Remove accidentally-public methods from QuantumCircuit (#13893)
• Ignoring unsupported gates for Solovay-Kitaev transpiler pass (#13690)
• Change the register name for measure_active to meas (#13866)
• Warn on use of property_set kwarg to BasePassManger.run (#13821)
• Ensure translation stage always outputs ISA circuits (#13792)
• Add default translation stage plugin (#13794)
• Add unitary gate representation to rust (#13759)
• Have BlueprintCircuit.copy_empty_like return an empty QuantumCircuit (#13782)
• Bump MSRV to 1.79 (#13709)

Removed

• Update transpiler pipeline to (only) use target internally (#12850)
• Remove pulse module files, pulse visualization and final cleanup (#13872)
• Remove deprecated BackendV1 elements, including base class, providers.models and qobj modules (#13793)
• Remove v1 primitive implementations (#13877)
• Remove calibrations APIs and related functionality (#13861)
• Remove fake backends based on BackendV1 and related tools (#13805)
• Remove Provider ABC (deprecated in 1.1) (#13435)
• Remove the classical_function module and all tweedledum-related code (#13815)
• Remove pulse support in QPY in 2.0 (#13814)
• Remove deprecated stochastic swap transpiler pass (#13791)
• The unused parameter dag in DAGNode constructor is removed (#13863)
• Remove condition/c_if, duration, and unit from instructions (#13506)
• Remove deprecated legacy scheduling passes (#13876)
• Remove use of BackendProperties (BackendV1) in transpiler pipeline (#13722)
• Remove pulse from GenericBackendV2 (#13829)
• Remove pulse-related passes (#13798)
• Remove assemble and assembler module (#13748)
• Remove use of deprecated objects in BasicSimulator (#13743)
• Remove sort_key attribute from DAGNode (#13736)
• Drop support for 32bit x86 linux and windows (#13650)
• Remove CXCancellation (deprecated in 1.1) (#13426)
• Remove deprecate_function and deprecate_arguments decorators (deprecated in 0.24) (#13448)

Fixed

• Fix qpy for MCMTGate (#14096) (#14118)
• Consistent sparse list format in sparse operators (#14067) (#14110)
• Fix ignored errors/durations in generate_preset_pass_manager if dt is set (#14065) (#14098)
• Fix global phase update in BasisTranslator Pass (backport #14078) (#14092)
• Fixes to various graphs in the docs (#14055) (#14076)
• Fix deepcopy/pickle of DAGCircuit variable IO nodes (backport #14041) (#14044)
• Introduce custom sympy srepr parser [stable/2.0] (#14023)
• Introduce custom sympy srepr parser [stable/1.4] (#14022)
• Preserve bit locations through pickle (backport #13980) (#14011)
• Fix string and standard gate mismatch in commutation checker (backport #13991) (#14004)
• Preserve bit locations through pickle (#13981)
• fix missing inverse definitions in generate_basis_approximations (#13517) (#13964)
• fix missing inverse definitions in generate_basis_approximations (#13517)
• Delegate BasePass.__call__ to PassManager.run (#13820)
• Use average gate fidelity in the commutation checker (#13874)
• Add 2q fractional gates to the ConsolidateBlocks transpiler pass (#13884)
• Fix qpy serialization of substitution of type ParameterExpression (backport #13890) (#13943)
• Fix qpy serialization of substitution of type ParameterExpression (#13890)
• Circuits with control flow now raise a proper error when circuit_to_instruction is called (#13921)
• Propagate DAGCircuit.name in ApplyLayout (#13910) (#13920)
• Propagate DAGCircuit.name in ApplyLayout (#13910)
• Fixing definition method for PyGate and PyInstruction (#13777)
• Applying a slight perturbation for ill-conditioned matrices (#13882) (#13889)
• Applying a slight perturbation for ill-conditioned matrices (#13882)
• Fix incorrect stop time bug #8729 (#11097) (#13843)
• Fix incorrect stop time bug #8729 (#11097)
• Fix tracking of routing permutation in Sabre with disjoint backends (#13833) (#13835)
• Fix tracking of routing permutation in Sabre with disjoint backends (#13833)
• Consider unit in Delay comparisons (#13816) (#13827)
• Consider unit in Delay comparisons (#13816)
• Do not contract control-flow operations during SabreSwap (#13790)
• Correctly updating global phase when removing gates that are identity up to a global phase (backport #13785) (#13825)
• Correctly updating global phase when removing gates that are identity up to a global phase (#13785)
• Fix CommutationChecker for 2q Pauli rotations (#13762) (#13804)
• Fix CommutationChecker for 2q Pauli rotations (#13762)
• Fix barrier label position when bits are reversed (#13780) (#13789)
• Fix barrier label position when bits are reversed (#13780)
• Fix random_clifford (#13606) (#13710)
• Fix 4-pi periodicity of controlled rotations in the CommutationChecker (#13670) (#13676)
• More conservative caching in the CommutationChecker (#13600) (#13677)
• Fix 4-pi periodicity of controlled rotations in the CommutationChecker (#13670)
• Fix an error in qasm3 exporter when operating on unitary gates (#13633) (#13663)
• Fix an error in qasm3 exporter when operating on unitary gates (#13633)
• Fix PauliEvolutionGate (using product formulas) for all-identity Pauli terms (#13634) (#13658)
• Fix PauliEvolutionGate (using product formulas) for all-identity Pauli terms (#13634)
• Fix UnitarySynthesis pass bug when target contains global gates (#13651) (#13656)
• Fix Target.instruction_supported when target.num_qubits == None (#13655) (#13657)
• Fix Target.instruction_supported when target.num_qubits == None (#13655)
• Fix UnitarySynthesis pass bug when target contains global gates (#13651)
• fix the 0 complex part (#13643) (#13646)
• fix the 0 complex part (#13643)
• Fix phase of `pauli_list.insert(..., qubit=Tru...

Changelog

Fixed

• Introduce custom sympy srepr parser [stable/2.0] (#14023)
• Preserve bit locations through pickle (backport #13980) (#14011)
• Fix string and standard gate mismatch in commutation checker (backport #13991) (#14004)

Changelog

Fixed

• Introduce custom sympy srepr parser [stable/1.4] (#14022)
• Preserve bit locations through pickle (#13981)
• fix missing inverse definitions in generate_basis_approximations (#13517) (#13964)