Changelog

Deprecated

• Cleanup leftover SamplePulse mentions (#4730)
• Update plots to work with quantum state classes (#4324)
• Create metaclass to handle tolerances through atol and rtol for Operators and States (#4141)
• Finish issue 4167: SamplePulse->Waveform (#4670)
• Finish issue 4168 (#4662)
• Remove the interactive visualizations (#4438)
• New mpl drawer fixes open issues and adds proportional font text width spacing and labels (#4616)
• Removing condition argument from apply_operation_back (#4135)
• Circuit reverse_bits operation (#4509)
• Unused variables (such as qasm(..., prec)) are being removed (#4192)
• Cache dag qubits/clbits (#4535)
• Remove deprecated multi-qubit acquire instructions (#4505)

Added

• Support for backends with defective qubits and gates (#4782)
• Allow Generator object for seed in QuantumVolume circuit (#4867)
• Sqrt(X) and C-Sqrt(X) gates (#4638)
• Add U and Phase gate (#4765)
• Quadratic form on binary variables circuit (#4800)
• Add synthesis-based translation method. (#4763)
• add global_phase to QuantumCircuit class (#4565)
• Add fake backends for Bogota, Montreal, and Toronto (#4733)
• Add phase estimation circuit to the library (#4685)
• Ancilla qubit type (#4686)
• Pulse builder interface (#4174)
• Add Counts object (#4501)
• Circuit control (#4627)
• Parameter conjugate (#4619)
• Adds BasisTanslator, UnrollCustomDefinitions to default levels. (#4446)
• Sabre layout and routing transpiler passes (#4537)
• Circuit reverse_bits operation (#4509)
• Add SetPhase instruction to pulse (#4540)
• Add rep delay (#4539)
• Add circuit.repeat (#4521)
• Add DAGDependency (#3581)
• Add BasisTranslator and UnrollCustomDefinitions passes. (#4442)
• Add from_networkx method to DAGCircuit class (#4255)
• Add ShiftFrequency instruction to pulse (#4390)
• Add init qubits flag to qobj (#4432)
• add DensityMatrix.to_statevector() for pure states (#4433)
• Add equivalence_library kwarg to circuit_to_{gate,inst} converters. (#4431)
• Update qsphere plots to show state labels and phases (#4384)
• Add support for substituting a Parameter with a ParameterExpression. (#4200)
• Add len to Schedule in Pulse along with related tests. (#4394)
• Add shift frequency qobj instruction - shiftf to schema (#4359)
• Add EquivalenceLibrary.draw() method. (#4196)

Changed

• Update plots to work with quantum state classes (#4324)
• Create metaclass to handle tolerances through atol and rtol for Operators and States (#4141)
• Finish issue 4167: SamplePulse->Waveform (#4670)
• Finish issue 4168 (#4662)
• Removing condition argument from apply_operation_back (#4135)
• QuantumCircuit.to_gate(..., label=...) support (#4478)
• Bugfix: Modified Pulse Style to default to RCParams. (#4470)
• fixed issue 4391 by updating idle_wires() in dagcircuit (#4481)
• Adding support for cregbundle in latex drawer (#4410)
• Allow transformation passes to modify the property set (#4387)
• Rename rescheduler to transform (#4251)
• Remove marshmallow from result/ and requirements (#4030)

Removed

• Remove switchable DAGCircuit implementation (#4386)
• Remove the interactive visualizations (#4438)
• remove deprecated qi functions (#4579)
• Remove almost-one-year-old deprecated methods (warning was inserted in #2683) (#4498)
• remove draw(..., line_length, ...) (deprecated after #3108) (#4507)
• Draw method: remove deprecated channels_to_plot argument (#4508)
• Remove deprecated multi-qubit acquire instructions (#4505)
• Remove circuit_instruction_map deprecated attribute (#4503)
• Remove marshmallow from result/ and requirements (#4030)

Fixed

• Drawers support for "partial" layout (#4795)
• fix dag_visualization in windows (#4794)
• Allow numbers.Integral instead of only built-in int for QuantumRegister index (#4591)
• pi_check qasm includes * between num and pi (#4732)
• Fix broadcast acquire config (#4654)
• QuantumCircuit.num_nonlocal_gates to count only Gate instances. (#4517)
• Fixes DAGCircuit.substitute_node_with_dag mutating input_dag if node has a condition (#4734)
• Fix transpiler failure with circuits containing conditions (#4695)
• Fix cnot method on QuantumCircuit (#4713)
• For DAGCircuit.compose remap condition bits (#4626)
• Fixes bug with cregbundle and conditional gates (#4597)
• New mpl drawer fixes open issues and adds proportional font text width spacing and labels (#4616)
• Add composite circuit definition when calling circuit.qasm() (#3748)
• disallow specifying controlled gate with zero controls. (#4584)
• fixes issue of crashing on unroll of 3+ qubit gates (#4577). (#4596)
• Issue #4182 Initializer should use at most 2^(n+1)-2n cnots (#4183)
• Fix ZZFeatureMap barriers (#4586)
• Set register name for definition of ControlledGates with ctrl_state. (#4582)
• Give MCX implementations more specific names. (#4568)
• Added num_ctrl_bits and ctrl_state to UnitaryGate call to ControlledGate (#4551)
• fix bug in unrolling open controlled basis gates. (#4444)
• Cache dag qubits/clbits (#4535)
• fixed issue 4391 by updating idle_wires() in dagcircuit (#4481)
• Fix #4445 | Bug in scheduler if circuit is empty (#4472)
• Fix disassemble of isometry and added test_disassemble_isometry (#4402)
• Circuit library NLocal string circuit drawer issue (#4468)
• Bugfix: Hz -> GHz conversion for SetFrequency -> PulseQobjInstruction (#4399)
• label support for controlled unitary (#4429)
• Allow bypassing parallel mode at init (#4345)
• MPL circuit drawer can handle multiple super/sub script commands in register name (#3827)
• Fix import of deprecated gates from qiskit.extensions (#4366)