Source code for braket.circuits.circuit

# Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

from __future__ import annotations

import warnings
from numbers import Number
from typing import Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Type, TypeVar, Union

import numpy as np

from braket.circuits import compiler_directives
from braket.circuits.ascii_circuit_diagram import AsciiCircuitDiagram
from braket.circuits.free_parameter import FreeParameter
from braket.circuits.free_parameter_expression import FreeParameterExpression
from braket.circuits.gate import Gate
from braket.circuits.instruction import Instruction
from braket.circuits.moments import Moments
from braket.circuits.noise import Noise
from braket.circuits.noise_helpers import (
    apply_noise_to_gates,
    apply_noise_to_moments,
    check_noise_target_gates,
    check_noise_target_qubits,
    check_noise_target_unitary,
    wrap_with_list,
)
from braket.circuits.observable import Observable
from braket.circuits.observables import TensorProduct
from braket.circuits.parameterizable import Parameterizable
from braket.circuits.qubit import QubitInput
from braket.circuits.qubit_set import QubitSet, QubitSetInput
from braket.circuits.result_type import ObservableResultType, ResultType
from braket.circuits.serialization import (
    IRType,
    OpenQASMSerializationProperties,
    QubitReferenceType,
    SerializationProperties,
)
from braket.circuits.unitary_calculation import calculate_unitary, calculate_unitary_big_endian
from braket.ir.jaqcd import Program as JaqcdProgram
from braket.ir.openqasm import Program as OpenQasmProgram

SubroutineReturn = TypeVar(
    "SubroutineReturn", Iterable[Instruction], Instruction, ResultType, Iterable[ResultType]
)
SubroutineCallable = TypeVar("SubroutineCallable", bound=Callable[..., SubroutineReturn])
AddableTypes = TypeVar("AddableTypes", SubroutineReturn, SubroutineCallable)


[docs]class Circuit: """ A representation of a quantum circuit that contains the instructions to be performed on a quantum device and the requested result types. See :mod:`braket.circuits.gates` module for all of the supported instructions. See :mod:`braket.circuits.result_types` module for all of the supported result types. `AddableTypes` are `Instruction`, iterable of `Instruction`, `ResultType`, iterable of `ResultType`, or `SubroutineCallable` """ _ALL_QUBITS = "ALL" # Flag to indicate all qubits in _qubit_observable_mapping
[docs] @classmethod def register_subroutine(cls, func: SubroutineCallable) -> None: """ Register the subroutine `func` as an attribute of the `Circuit` class. The attribute name is the name of `func`. Args: func (SubroutineCallable): The function of the subroutine to add to the class. Examples: >>> def h_on_all(target): ... circ = Circuit() ... for qubit in target: ... circ += Instruction(Gate.H(), qubit) ... return circ ... >>> Circuit.register_subroutine(h_on_all) >>> circ = Circuit().h_on_all(range(2)) >>> for instr in circ.instructions: ... print(instr) ... Instruction('operator': 'H', 'target': QubitSet(Qubit(0),)) Instruction('operator': 'H', 'target': QubitSet(Qubit(1),)) """ def method_from_subroutine(self, *args, **kwargs) -> SubroutineReturn: return self.add(func, *args, **kwargs) function_name = func.__name__ setattr(cls, function_name, method_from_subroutine) function_attr = getattr(cls, function_name) setattr(function_attr, "__doc__", func.__doc__)
def __init__(self, addable: AddableTypes = None, *args, **kwargs): """ Args: addable (AddableTypes): The item(s) to add to self. Default = None. Raises: TypeError: If `addable` is an unsupported type. Examples: >>> circ = Circuit([Instruction(Gate.H(), 4), Instruction(Gate.CNot(), [4, 5])]) >>> circ = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().h(0).cnot(0, 1).probability([0, 1]) >>> @circuit.subroutine(register=True) >>> def bell_pair(target): ... return Circ().h(target[0]).cnot(target[0:2]) ... >>> circ = Circuit(bell_pair, [4,5]) >>> circ = Circuit().bell_pair([4,5]) """ self._moments: Moments = Moments() self._result_types: Dict[ResultType] = {} self._qubit_observable_mapping: Dict[Union[int, Circuit._ALL_QUBITS], Observable] = {} self._qubit_observable_target_mapping: Dict[int, Tuple[int]] = {} self._qubit_observable_set = set() self._parameters = set() self._observables_simultaneously_measurable = True self._has_compiler_directives = False if addable is not None: self.add(addable, *args, **kwargs) @property def depth(self) -> int: """int: Get the circuit depth.""" return self._moments.depth @property def instructions(self) -> List[Instruction]: """Iterable[Instruction]: Get an `iterable` of instructions in the circuit.""" return list(self._moments.values()) @property def result_types(self) -> List[ResultType]: """List[ResultType]: Get a list of requested result types in the circuit.""" return list(self._result_types.keys()) @property def basis_rotation_instructions(self) -> List[Instruction]: """Gets a list of basis rotation instructions. Returns: List[Instruction]: Get a list of basis rotation instructions in the circuit. These basis rotation instructions are added if result types are requested for an observable other than Pauli-Z. This only makes sense if all observables are simultaneously measurable; if not, this method will return an empty list. """ # Note that basis_rotation_instructions can change each time a new instruction # is added to the circuit because `self._moments.qubits` would change basis_rotation_instructions = [] all_qubit_observable = self._qubit_observable_mapping.get(Circuit._ALL_QUBITS) if all_qubit_observable: for target in self.qubits: basis_rotation_instructions += Circuit._observable_to_instruction( all_qubit_observable, target ) return basis_rotation_instructions target_lists = sorted(set(self._qubit_observable_target_mapping.values())) for target_list in target_lists: observable = self._qubit_observable_mapping[target_list[0]] basis_rotation_instructions += Circuit._observable_to_instruction( observable, target_list ) return basis_rotation_instructions @staticmethod def _observable_to_instruction( observable: Observable, target_list: List[int] ) -> List[Instruction]: return [Instruction(gate, target_list) for gate in observable.basis_rotation_gates] @property def moments(self) -> Moments: """Moments: Get the `moments` for this circuit. Note that this includes observables.""" return self._moments @property def qubit_count(self) -> int: """Get the qubit count for this circuit. Note that this includes observables. Returns: int: The qubit count for this circuit. """ all_qubits = self._moments.qubits.union(self._qubit_observable_set) return len(all_qubits) @property def qubits(self) -> QubitSet: """QubitSet: Get a copy of the qubits for this circuit.""" return QubitSet(self._moments.qubits.union(self._qubit_observable_set)) @property def parameters(self) -> Set[FreeParameter]: """ Gets a set of the parameters in the Circuit. Returns: Set[FreeParameter]: The `FreeParameters` in the Circuit. """ return self._parameters
[docs] def add_result_type( self, result_type: ResultType, target: QubitSetInput = None, target_mapping: Dict[QubitInput, QubitInput] = None, ) -> Circuit: """ Add a requested result type to `self`, returns `self` for chaining ability. Args: result_type (ResultType): `ResultType` to add into `self`. target (QubitSetInput): Target qubits for the `result_type`. Default = `None`. target_mapping (Dict[QubitInput, QubitInput]): A dictionary of qubit mappings to apply to the `result_type.target`. Key is the qubit in `result_type.target` and the value is what the key will be changed to. Default = `None`. Returns: Circuit: self Note: Target and target_mapping will only be applied to those requested result types with the attribute `target`. The result_type will be appended to the end of the dict keys of `circuit.result_types` only if it does not already exist in `circuit.result_types` Raises: TypeError: If both `target_mapping` and `target` are supplied. Examples: >>> result_type = ResultType.Probability(target=[0, 1]) >>> circ = Circuit().add_result_type(result_type) >>> print(circ.result_types[0]) Probability(target=QubitSet([Qubit(0), Qubit(1)])) >>> result_type = ResultType.Probability(target=[0, 1]) >>> circ = Circuit().add_result_type(result_type, target_mapping={0: 10, 1: 11}) >>> print(circ.result_types[0]) Probability(target=QubitSet([Qubit(10), Qubit(11)])) >>> result_type = ResultType.Probability(target=[0, 1]) >>> circ = Circuit().add_result_type(result_type, target=[10, 11]) >>> print(circ.result_types[0]) Probability(target=QubitSet([Qubit(10), Qubit(11)])) >>> result_type = ResultType.StateVector() >>> circ = Circuit().add_result_type(result_type) >>> print(circ.result_types[0]) StateVector() """ if target_mapping and target is not None: raise TypeError("Only one of 'target_mapping' or 'target' can be supplied.") if not target_mapping and not target: # Nothing has been supplied, add result_type result_type_to_add = result_type elif target_mapping: # Target mapping has been supplied, copy result_type result_type_to_add = result_type.copy(target_mapping=target_mapping) else: # ResultType with target result_type_to_add = result_type.copy(target=target) if result_type_to_add not in self._result_types: observable = Circuit._extract_observable(result_type_to_add) if observable and self._observables_simultaneously_measurable: # Only check if all observables can be simultaneously measured self._add_to_qubit_observable_mapping(observable, result_type_to_add.target) self._add_to_qubit_observable_set(result_type_to_add) # using dict as an ordered set, value is arbitrary self._result_types[result_type_to_add] = None return self
@staticmethod def _extract_observable(result_type: ResultType) -> Optional[Observable]: if isinstance(result_type, ResultType.Probability): return Observable.Z() # computational basis elif isinstance(result_type, ObservableResultType): return result_type.observable else: return None def _add_to_qubit_observable_mapping( self, observable: Observable, observable_target: QubitSet ) -> None: targets = observable_target or list(self._qubit_observable_set) all_qubits_observable = self._qubit_observable_mapping.get(Circuit._ALL_QUBITS) tensor_product_dict = ( Circuit._tensor_product_index_dict(observable, observable_target) if isinstance(observable, TensorProduct) else None ) identity = Observable.I() for i in range(len(targets)): target = targets[i] new_observable = tensor_product_dict[i][0] if tensor_product_dict else observable current_observable = all_qubits_observable or self._qubit_observable_mapping.get(target) add_observable = not current_observable or ( current_observable == identity and new_observable != identity ) if ( not add_observable and current_observable != identity and new_observable != identity and current_observable != new_observable ): return self._encounter_noncommuting_observable() if observable_target: new_targets = ( tensor_product_dict[i][1] if tensor_product_dict else tuple(observable_target) ) if add_observable: self._qubit_observable_target_mapping[target] = new_targets self._qubit_observable_mapping[target] = new_observable elif new_observable.qubit_count > 1: current_target = self._qubit_observable_target_mapping.get(target) if current_target and current_target != new_targets: return self._encounter_noncommuting_observable() if not observable_target and observable != identity: if all_qubits_observable and all_qubits_observable != observable: return self._encounter_noncommuting_observable() self._qubit_observable_mapping[Circuit._ALL_QUBITS] = observable @staticmethod def _tensor_product_index_dict( observable: TensorProduct, observable_target: QubitSet ) -> Dict[int, Tuple[Observable, Tuple[int, ...]]]: obj_dict = {} i = 0 factors = list(observable.factors) total = factors[0].qubit_count while factors: if i >= total: factors.pop(0) if factors: total += factors[0].qubit_count if factors: first = total - factors[0].qubit_count obj_dict[i] = (factors[0], tuple(observable_target[first:total])) i += 1 return obj_dict def _add_to_qubit_observable_set(self, result_type: ResultType) -> None: if isinstance(result_type, ObservableResultType) and result_type.target: self._qubit_observable_set.update(result_type.target)
[docs] def add_instruction( self, instruction: Instruction, target: QubitSetInput = None, target_mapping: Dict[QubitInput, QubitInput] = None, ) -> Circuit: """ Add an instruction to `self`, returns `self` for chaining ability. Args: instruction (Instruction): `Instruction` to add into `self`. target (QubitSetInput): Target qubits for the `instruction`. If a single qubit gate, an instruction is created for every index in `target`. Default = `None`. target_mapping (Dict[QubitInput, QubitInput]): A dictionary of qubit mappings to apply to the `instruction.target`. Key is the qubit in `instruction.target` and the value is what the key will be changed to. Default = `None`. Returns: Circuit: self Raises: TypeError: If both `target_mapping` and `target` are supplied. Examples: >>> instr = Instruction(Gate.CNot(), [0, 1]) >>> circ = Circuit().add_instruction(instr) >>> print(circ.instructions[0]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(0), Qubit(1))) >>> instr = Instruction(Gate.CNot(), [0, 1]) >>> circ = Circuit().add_instruction(instr, target_mapping={0: 10, 1: 11}) >>> print(circ.instructions[0]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(10), Qubit(11))) >>> instr = Instruction(Gate.CNot(), [0, 1]) >>> circ = Circuit().add_instruction(instr, target=[10, 11]) >>> print(circ.instructions[0]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(10), Qubit(11))) >>> instr = Instruction(Gate.H(), 0) >>> circ = Circuit().add_instruction(instr, target=[10, 11]) >>> print(circ.instructions[0]) Instruction('operator': 'H', 'target': QubitSet(Qubit(10),)) >>> print(circ.instructions[1]) Instruction('operator': 'H', 'target': QubitSet(Qubit(11),)) """ if target_mapping and target is not None: raise TypeError("Only one of 'target_mapping' or 'target' can be supplied.") if not target_mapping and not target: # Nothing has been supplied, add instruction instructions_to_add = [instruction] elif target_mapping: # Target mapping has been supplied, copy instruction instructions_to_add = [instruction.copy(target_mapping=target_mapping)] elif hasattr(instruction.operator, "qubit_count") and instruction.operator.qubit_count == 1: # single qubit operator with target, add an instruction for each target instructions_to_add = [instruction.copy(target=qubit) for qubit in target] else: # non single qubit operator with target, add instruction with target instructions_to_add = [instruction.copy(target=target)] if self._check_for_params(instruction): for param in instruction.operator.parameters: free_params = param.expression.free_symbols for parameter in free_params: self._parameters.add(FreeParameter(parameter.name)) self._moments.add(instructions_to_add) return self
def _check_for_params(self, instruction: Instruction) -> bool: """ This checks for free parameters in an :class:{Instruction}. Checks children classes of :class:{Parameterizable}. Args: instruction (Instruction): The instruction to check for a :class:{FreeParameterExpression}. Returns: bool: Whether an object is parameterized. """ return issubclass(type(instruction.operator), Parameterizable) and any( issubclass(type(param), FreeParameterExpression) for param in instruction.operator.parameters )
[docs] def add_circuit( self, circuit: Circuit, target: QubitSetInput = None, target_mapping: Dict[QubitInput, QubitInput] = None, ) -> Circuit: """ Add a `circuit` to self, returns self for chaining ability. Args: circuit (Circuit): Circuit to add into self. target (QubitSetInput): Target qubits for the supplied circuit. This is a macro over `target_mapping`; `target` is converted to a `target_mapping` by zipping together a sorted `circuit.qubits` and `target`. Default = `None`. target_mapping (Dict[QubitInput, QubitInput]): A dictionary of qubit mappings to apply to the qubits of `circuit.instructions`. Key is the qubit to map, and the value is what to change it to. Default = `None`. Returns: Circuit: self Raises: TypeError: If both `target_mapping` and `target` are supplied. Note: Supplying `target` sorts `circuit.qubits` to have deterministic behavior since `circuit.qubits` ordering is based on how instructions are inserted. Use caution when using this with circuits that with a lot of qubits, as the sort can be resource-intensive. Use `target_mapping` to use a linear runtime to remap the qubits. Requested result types of the circuit that will be added will be appended to the end of the list for the existing requested result types. A result type to be added that is equivalent to an existing requested result type will not be added. Examples: >>> widget = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().add_circuit(widget) >>> instructions = list(circ.instructions) >>> print(instructions[0]) Instruction('operator': 'H', 'target': QubitSet(Qubit(0),)) >>> print(instructions[1]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(0), Qubit(1))) >>> widget = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().add_circuit(widget, target_mapping={0: 10, 1: 11}) >>> instructions = list(circ.instructions) >>> print(instructions[0]) Instruction('operator': 'H', 'target': QubitSet(Qubit(10),)) >>> print(instructions[1]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(10), Qubit(11))) >>> widget = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().add_circuit(widget, target=[10, 11]) >>> instructions = list(circ.instructions) >>> print(instructions[0]) Instruction('operator': 'H', 'target': QubitSet(Qubit(10),)) >>> print(instructions[1]) Instruction('operator': 'CNOT', 'target': QubitSet(Qubit(10), Qubit(11))) """ if target_mapping and target is not None: raise TypeError("Only one of 'target_mapping' or 'target' can be supplied.") elif target is not None: keys = sorted(circuit.qubits) values = target target_mapping = dict(zip(keys, values)) for instruction in circuit.instructions: self.add_instruction(instruction, target_mapping=target_mapping) for result_type in circuit.result_types: self.add_result_type(result_type, target_mapping=target_mapping) return self
[docs] def add_verbatim_box( self, verbatim_circuit: Circuit, target: QubitSetInput = None, target_mapping: Dict[QubitInput, QubitInput] = None, ) -> Circuit: """ Add a verbatim `circuit` to self, that is, ensures that `circuit` is not modified in any way by the compiler. Args: verbatim_circuit (Circuit): Circuit to add into self. target (QubitSetInput): Target qubits for the supplied circuit. This is a macro over `target_mapping`; `target` is converted to a `target_mapping` by zipping together a sorted `circuit.qubits` and `target`. Default = `None`. target_mapping (Dict[QubitInput, QubitInput]): A dictionary of qubit mappings to apply to the qubits of `circuit.instructions`. Key is the qubit to map, and the value is what to change it to. Default = `None`. Returns: Circuit: self Raises: TypeError: If both `target_mapping` and `target` are supplied. ValueError: If `circuit` has result types attached Examples: >>> widget = Circuit().h(0).h(1) >>> circ = Circuit().add_verbatim_box(widget) >>> print(list(circ.instructions)) [Instruction('operator': StartVerbatimBox, 'target': QubitSet([])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(0)])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(1)])), Instruction('operator': EndVerbatimBox, 'target': QubitSet([]))] >>> widget = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().add_verbatim_box(widget, target_mapping={0: 10, 1: 11}) >>> print(list(circ.instructions)) [Instruction('operator': StartVerbatimBox, 'target': QubitSet([])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(10)])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(11)])), Instruction('operator': EndVerbatimBox, 'target': QubitSet([]))] >>> widget = Circuit().h(0).cnot(0, 1) >>> circ = Circuit().add_verbatim_box(widget, target=[10, 11]) >>> print(list(circ.instructions)) [Instruction('operator': StartVerbatimBox, 'target': QubitSet([])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(10)])), Instruction('operator': H('qubit_count': 1), 'target': QubitSet([Qubit(11)])), Instruction('operator': EndVerbatimBox, 'target': QubitSet([]))] """ if target_mapping and target is not None: raise TypeError("Only one of 'target_mapping' or 'target' can be supplied.") elif target is not None: keys = sorted(verbatim_circuit.qubits) values = target target_mapping = dict(zip(keys, values)) if verbatim_circuit.result_types: raise ValueError("Verbatim subcircuit is not measured and cannot have result types") if verbatim_circuit.instructions: self.add_instruction(Instruction(compiler_directives.StartVerbatimBox())) for instruction in verbatim_circuit.instructions: self.add_instruction(instruction, target_mapping=target_mapping) self.add_instruction(Instruction(compiler_directives.EndVerbatimBox())) self._has_compiler_directives = True return self
[docs] def apply_gate_noise( self, noise: Union[Type[Noise], Iterable[Type[Noise]]], target_gates: Optional[Union[Type[Gate], Iterable[Type[Gate]]]] = None, target_unitary: np.ndarray = None, target_qubits: Optional[QubitSetInput] = None, ) -> Circuit: """Apply `noise` to the circuit according to `target_gates`, `target_unitary` and `target_qubits`. For any parameter that is None, that specification is ignored (e.g. if `target_gates` is None then the noise is applied after every gate in `target_qubits`). If `target_gates` and `target_qubits` are both None, then `noise` is applied to every qubit after every gate. Noise is either applied to `target_gates` or `target_unitary`, so they cannot be provided at the same time. When `noise.qubit_count` == 1, ie. `noise` is single-qubit, `noise` is added to all qubits in `target_gates` or `target_unitary` (or to all qubits in `target_qubits` if `target_gates` is None). When `noise.qubit_count` > 1 and `target_gates` is not None, the number of qubits of any gate in `target_gates` must be the same as `noise.qubit_count`. When `noise.qubit_count` > 1, `target_gates` and `target_unitary` is None, noise is only applied to gates with the same qubit_count in target_qubits. Args: noise (Union[Type[Noise], Iterable[Type[Noise]]]): Noise channel(s) to be applied to the circuit. target_gates (Optional[Union[Type[Gate], Iterable[Type[Gate]]]]): Gate class or List of Gate classes which `noise` is applied to. Default=None. target_unitary (ndarray): matrix of the target unitary gates. Default=None. target_qubits (Optional[QubitSetInput]): Index or indices of qubit(s). Default=None. Returns: Circuit: self Raises: TypeError: If `noise` is not Noise type. If `target_gates` is not a Gate type, Iterable[Gate]. If `target_unitary` is not a np.ndarray type. If `target_qubits` has non-integers or negative integers. IndexError: If applying noise to an empty circuit. If `target_qubits` is out of range of circuit.qubits. ValueError: If both `target_gates` and `target_unitary` are provided. If `target_unitary` is not a unitary. If `noise` is multi-qubit noise and `target_gates` contain gates with the number of qubits not the same as `noise.qubit_count`. Warning: If `noise` is multi-qubit noise while there is no gate with the same number of qubits in `target_qubits` or in the whole circuit when `target_qubits` is not given. If no `target_gates` or `target_unitary` exist in `target_qubits` or in the whole circuit when they are not given. Examples: >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ) T : |0|1|2| q0 : -X-Z-C- | q1 : -Y-X-X- T : |0|1|2| >>> noise = Noise.Depolarizing(probability=0.1) >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_gate_noise(noise, target_gates = Gate.X)) T : | 0 | 1 |2| q0 : -X-DEPO(0.1)-Z-----------C- | q1 : -Y-----------X-DEPO(0.1)-X- T : | 0 | 1 |2| >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_gate_noise(noise, target_qubits = 1)) T : | 0 | 1 | 2 | q0 : -X-----------Z-----------C----------- | q1 : -Y-DEPO(0.1)-X-DEPO(0.1)-X-DEPO(0.1)- T : | 0 | 1 | 2 | >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_gate_noise(noise, ... target_gates = [Gate.X,Gate.Y], ... target_qubits = [0,1]) ... ) T : | 0 | 1 |2| q0 : -X-DEPO(0.1)-Z-----------C- | q1 : -Y-DEPO(0.1)-X-DEPO(0.1)-X- T : | 0 | 1 |2| """ # check whether gate noise is applied to an empty circuit if not self.qubits: raise IndexError("Gate noise cannot be applied to an empty circuit.") # check if target_gates and target_unitary are both given if (target_unitary is not None) and (target_gates is not None): raise ValueError("target_unitary and target_gates cannot be input at the same time.") # check target_qubits target_qubits = check_noise_target_qubits(self, target_qubits) if not all(qubit in self.qubits for qubit in target_qubits): raise IndexError("target_qubits must be within the range of the current circuit.") # make noise a list noise = wrap_with_list(noise) # make target_gates a list if target_gates is not None: target_gates = wrap_with_list(target_gates) # remove duplicate items target_gates = list(dict.fromkeys(target_gates)) for noise_channel in noise: if not isinstance(noise_channel, Noise): raise TypeError("Noise must be an instance of the Noise class") # check whether target_gates is valid if target_gates is not None: check_noise_target_gates(noise_channel, target_gates) if target_unitary is not None: check_noise_target_unitary(noise_channel, target_unitary) if target_unitary is not None: return apply_noise_to_gates(self, noise, target_unitary, target_qubits) else: return apply_noise_to_gates(self, noise, target_gates, target_qubits)
[docs] def apply_initialization_noise( self, noise: Union[Type[Noise], Iterable[Type[Noise]]], target_qubits: Optional[QubitSetInput] = None, ) -> Circuit: """Apply `noise` at the beginning of the circuit for every qubit (default) or target_qubits`. Only when `target_qubits` is given can the noise be applied to an empty circuit. When `noise.qubit_count` > 1, the number of qubits in target_qubits must be equal to `noise.qubit_count`. Args: noise (Union[Type[Noise], Iterable[Type[Noise]]]): Noise channel(s) to be applied to the circuit. target_qubits (Optional[QubitSetInput]): Index or indices of qubit(s). Default=None. Returns: Circuit: self Raises: TypeError: If `noise` is not Noise type. If `target_qubits` has non-integers or negative integers. IndexError: If applying noise to an empty circuit when `target_qubits` is not given. ValueError: If `noise.qubit_count` > 1 and the number of qubits in target_qubits is not the same as `noise.qubit_count`. Examples: >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ) >>> noise = Noise.Depolarizing(probability=0.1) >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_initialization_noise(noise)) >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_initialization_noise(noise, target_qubits = 1)) >>> circ = Circuit() >>> print(circ.apply_initialization_noise(noise, target_qubits = [0, 1])) """ if (len(self.qubits) == 0) and (target_qubits is None): raise IndexError( "target_qubits must be provided in order to" " apply the initialization noise to an empty circuit." ) target_qubits = check_noise_target_qubits(self, target_qubits) # make noise a list noise = wrap_with_list(noise) for noise_channel in noise: if not isinstance(noise_channel, Noise): raise TypeError("Noise must be an instance of the Noise class") if noise_channel.qubit_count > 1 and noise_channel.qubit_count != len(target_qubits): raise ValueError( "target_qubits needs to be provided for this multi-qubit noise channel," " and the number of qubits in target_qubits must be the same as defined by" " the multi-qubit noise channel." ) return apply_noise_to_moments(self, noise, target_qubits, "initialization")
[docs] def make_bound_circuit(self, param_values: Dict[str, Number], strict: bool = False) -> Circuit: """ Binds FreeParameters based upon their name and values passed in. If parameters share the same name, all the parameters of that name will be set to the mapped value. Args: param_values (Dict[str, Number]): A mapping of FreeParameter names to a value to assign to them. strict (bool): If True, raises a ValueError if none of the FreeParameters in param_values appear in the circuit. False by default." Returns: Circuit: Returns a circuit with all present parameters fixed to their respective values. """ if strict: self._validate_parameters(param_values) return self._use_parameter_value(param_values)
def _validate_parameters(self, parameter_values: Dict[str, Number]) -> None: """ This runs a check to see that the parameters are in the Circuit. Args: parameter_values (Dict[str, Number]): A mapping of FreeParameter names to a value to assign to them. Raises: ValueError: If there are no parameters that match the key for the arg param_values. """ parameter_strings = set() for parameter in self.parameters: parameter_strings.add(str(parameter)) for param in parameter_values: if param not in parameter_strings: raise ValueError(f"No parameter in the circuit named: {param}") def _use_parameter_value(self, param_values: Dict[str, Number]) -> Circuit: """ Creates a Circuit that uses the parameter values passed in. Args: param_values (Dict[str, Number]): A mapping of FreeParameter names to a value to assign to them. Returns: Circuit: A Circuit with specified parameters swapped for their values. """ fixed_circ = Circuit() for val in param_values.values(): self._validate_parameter_value(val) for instruction in self.instructions: if self._check_for_params(instruction): fixed_circ.add( Instruction( instruction.operator.bind_values(**param_values), target=instruction.target ) ) else: fixed_circ.add(instruction) fixed_circ.add(self.result_types) return fixed_circ @staticmethod def _validate_parameter_value(val: Any) -> None: """ Validates the value being used is a Number. Args: val (Any): The value be verified. Raises: ValueError: If the value is not a Number """ if not isinstance(val, Number): raise ValueError( f"Parameters can only be assigned numeric values. " f"Invalid inputs: {val}" )
[docs] def apply_readout_noise( self, noise: Union[Type[Noise], Iterable[Type[Noise]]], target_qubits: Optional[QubitSetInput] = None, ) -> Circuit: """Apply `noise` right before measurement in every qubit (default) or target_qubits`. Only when `target_qubits` is given can the noise be applied to an empty circuit. When `noise.qubit_count` > 1, the number of qubits in target_qubits must be equal to `noise.qubit_count`. Args: noise (Union[Type[Noise], Iterable[Type[Noise]]]): Noise channel(s) to be applied to the circuit. target_qubits (Optional[QubitSetInput]): Index or indices of qubit(s). Default=None. Returns: Circuit: self Raises: TypeError: If `noise` is not Noise type. If `target_qubits` has non-integers. IndexError: If applying noise to an empty circuit. ValueError: If `target_qubits` has negative integers. If `noise.qubit_count` > 1 and the number of qubits in target_qubits is not the same as `noise.qubit_count`. Examples: >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ) >>> noise = Noise.Depolarizing(probability=0.1) >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_initialization_noise(noise)) >>> circ = Circuit().x(0).y(1).z(0).x(1).cnot(0,1) >>> print(circ.apply_initialization_noise(noise, target_qubits = 1)) >>> circ = Circuit() >>> print(circ.apply_initialization_noise(noise, target_qubits = [0, 1])) """ if (len(self.qubits) == 0) and (target_qubits is None): raise IndexError( "target_qubits must be provided in order to" " apply the readout noise to an empty circuit." ) if target_qubits is None: target_qubits = self.qubits else: if not isinstance(target_qubits, list): target_qubits = [target_qubits] if not all(isinstance(q, int) for q in target_qubits): raise TypeError("target_qubits must be integer(s)") if not all(q >= 0 for q in target_qubits): raise ValueError("target_qubits must contain only non-negative integers.") target_qubits = QubitSet(target_qubits) # make noise a list noise = wrap_with_list(noise) for noise_channel in noise: if not isinstance(noise_channel, Noise): raise TypeError("Noise must be an instance of the Noise class") if noise_channel.qubit_count > 1 and noise_channel.qubit_count != len(target_qubits): raise ValueError( "target_qubits needs to be provided for this multi-qubit noise channel," " and the number of qubits in target_qubits must be the same as defined by" " the multi-qubit noise channel." ) return apply_noise_to_moments(self, noise, target_qubits, "readout")
[docs] def add(self, addable: AddableTypes, *args, **kwargs) -> Circuit: """ Generic add method for adding item(s) to self. Any arguments that `add_circuit()` and / or `add_instruction()` and / or `add_result_type` supports are supported by this method. If adding a subroutine, check with that subroutines documentation to determine what input it allows. Args: addable (AddableTypes): The item(s) to add to self. Default = `None`. Returns: Circuit: self Raises: TypeError: If `addable` is an unsupported type See Also: `add_circuit()` `add_instruction()` `add_result_type()` Examples: >>> circ = Circuit().add([Instruction(Gate.H(), 4), Instruction(Gate.CNot(), [4, 5])]) >>> circ = Circuit().add([ResultType.StateVector()]) >>> circ = Circuit().h(4).cnot([4, 5]) >>> @circuit.subroutine() >>> def bell_pair(target): ... return Circuit().h(target[0]).cnot(target[0: 2]) ... >>> circ = Circuit().add(bell_pair, [4,5]) """ def _flatten(addable: Union[Iterable, AddableTypes]) -> AddableTypes: if isinstance(addable, Iterable): for item in addable: yield from _flatten(item) else: yield addable for item in _flatten(addable): if isinstance(item, Instruction): self.add_instruction(item, *args, **kwargs) elif isinstance(item, ResultType): self.add_result_type(item, *args, **kwargs) elif isinstance(item, Circuit): self.add_circuit(item, *args, **kwargs) elif callable(item): self.add(item(*args, **kwargs)) else: raise TypeError(f"Cannot add a '{type(item)}' to a Circuit") return self
[docs] def adjoint(self) -> Circuit: """Returns the adjoint of this circuit. This is the adjoint of every instruction of the circuit, in reverse order. Result types, and consequently basis rotations will stay in the same order at the end of the circuit. Returns: Circuit: The adjoint of the circuit. """ circ = Circuit() for instr in reversed(self.instructions): circ.add(instr.adjoint()) for result_type in self._result_types: circ.add_result_type(result_type) return circ
[docs] def diagram(self, circuit_diagram_class: Type = AsciiCircuitDiagram) -> str: """ Get a diagram for the current circuit. Args: circuit_diagram_class (Type): A `CircuitDiagram` class that builds the diagram for this circuit. Default = `AsciiCircuitDiagram`. Returns: str: An ASCII string circuit diagram. """ return circuit_diagram_class.build_diagram(self)
[docs] def to_ir( self, ir_type: IRType = IRType.JAQCD, serialization_properties: SerializationProperties = None, ) -> Union[OpenQasmProgram, JaqcdProgram]: """ Converts the circuit into the canonical intermediate representation. If the circuit is sent over the wire, this method is called before it is sent. Args: ir_type (IRType): The IRType to use for converting the circuit object to its IR representation. serialization_properties (SerializationProperties): The serialization properties to use while serializing the object to the IR representation. The serialization properties supplied must correspond to the supplied `ir_type`. Defaults to None. Returns: Union[OpenQasmProgram, JaqcdProgram]: A representation of the circuit in the `ir_type` format. Raises: ValueError: If the supplied `ir_type` is not supported, or if the supplied serialization properties don't correspond to the `ir_type`. """ if ir_type == IRType.JAQCD: return self._to_jaqcd() elif ir_type == IRType.OPENQASM: if serialization_properties and not isinstance( serialization_properties, OpenQASMSerializationProperties ): raise ValueError( "serialization_properties must be of type OpenQASMSerializationProperties " "for IRType.OPENQASM." ) return self._to_openqasm(serialization_properties or OpenQASMSerializationProperties()) else: raise ValueError(f"Supplied ir_type {ir_type} is not supported.")
def _to_jaqcd(self) -> JaqcdProgram: jaqcd_ir_type = IRType.JAQCD ir_instructions = [instr.to_ir(ir_type=jaqcd_ir_type) for instr in self.instructions] ir_results = [result_type.to_ir(ir_type=jaqcd_ir_type) for result_type in self.result_types] ir_basis_rotation_instructions = [ instr.to_ir(ir_type=jaqcd_ir_type) for instr in self.basis_rotation_instructions ] return JaqcdProgram.construct( instructions=ir_instructions, results=ir_results, basis_rotation_instructions=ir_basis_rotation_instructions, ) def _to_openqasm( self, serialization_properties: OpenQASMSerializationProperties ) -> OpenQasmProgram: ir_instructions = self._create_openqasm_header(serialization_properties) openqasm_ir_type = IRType.OPENQASM ir_instructions.extend( [ instruction.to_ir( ir_type=openqasm_ir_type, serialization_properties=serialization_properties ) for instruction in self.instructions ] ) if self.result_types: ir_instructions.extend( [ result_type.to_ir( ir_type=openqasm_ir_type, serialization_properties=serialization_properties ) for result_type in self.result_types ] ) else: for idx, qubit in enumerate(self.qubits): qubit_target = serialization_properties.format_target(int(qubit)) ir_instructions.append(f"b[{idx}] = measure {qubit_target};") return OpenQasmProgram.construct(source="\n".join(ir_instructions), inputs={}) def _create_openqasm_header( self, serialization_properties: OpenQASMSerializationProperties ) -> List[str]: ir_instructions = ["OPENQASM 3.0;"] for parameter in self.parameters: ir_instructions.append(f"input float {parameter};") if not self.result_types: ir_instructions.append(f"bit[{self.qubit_count}] b;") if serialization_properties.qubit_reference_type == QubitReferenceType.VIRTUAL: total_qubits = max(self.qubits).real + 1 ir_instructions.append(f"qubit[{total_qubits}] q;") elif serialization_properties.qubit_reference_type != QubitReferenceType.PHYSICAL: raise ValueError( f"Invalid qubit_reference_type " f"{serialization_properties.qubit_reference_type} supplied." ) return ir_instructions
[docs] def as_unitary(self) -> np.ndarray: r""" Returns the unitary matrix representation, in little endian format, of the entire circuit. *Note*: The performance of this method degrades with qubit count. It might be slow for qubit count > 10. Returns: ndarray: A numpy array with shape (2^qubit_count, 2^qubit_count) representing the circuit as a unitary. *Note*: For an empty circuit, an empty numpy array is returned (`array([], dtype=complex128)`) Warnings: This method has been deprecated, please use to_unitary() instead. The unitary returned by this method is *little-endian*; the first qubit in the circuit is the _least_ significant. For example, a circuit `Circuit().h(0).x(1)` will yield the unitary :math:`X(1) \otimes H(0)`. Raises: TypeError: If circuit is not composed only of `Gate` instances, i.e. a circuit with `Noise` operators will raise this error. Examples: >>> circ = Circuit().h(0).cnot(0, 1) >>> circ.as_unitary() array([[ 0.70710678+0.j, 0.70710678+0.j, 0. +0.j, 0. +0.j], [ 0. +0.j, 0. +0.j, 0.70710678+0.j, -0.70710678+0.j], [ 0. +0.j, 0. +0.j, 0.70710678+0.j, 0.70710678+0.j], [ 0.70710678+0.j, -0.70710678+0.j, 0. +0.j, 0. +0.j]]) """ warnings.warn( "Matrix returned will have qubits in little-endian order; " "This method has been deprecated. Please use to_unitary() instead.", category=DeprecationWarning, ) qubits = self.qubits if not qubits: return np.zeros(0, dtype=complex) qubit_count = max(qubits) + 1 return calculate_unitary(qubit_count, self.instructions)
[docs] def to_unitary(self) -> np.ndarray: """ Returns the unitary matrix representation of the entire circuit. Note: The performance of this method degrades with qubit count. It might be slow for `qubit count` > 10. Returns: np.ndarray: A numpy array with shape (2^qubit_count, 2^qubit_count) representing the circuit as a unitary. For an empty circuit, an empty numpy array is returned (`array([], dtype=complex)`) Raises: TypeError: If circuit is not composed only of `Gate` instances, i.e. a circuit with `Noise` operators will raise this error. Examples: >>> circ = Circuit().h(0).cnot(0, 1) >>> circ.to_unitary() array([[ 0.70710678+0.j, 0. +0.j, 0.70710678+0.j, 0. +0.j], [ 0. +0.j, 0.70710678+0.j, 0. +0.j, 0.70710678+0.j], [ 0. +0.j, 0.70710678+0.j, 0. +0.j, -0.70710678+0.j], [ 0.70710678+0.j, 0. +0.j, -0.70710678+0.j, 0. +0.j]]) """ qubits = self.qubits if not qubits: return np.zeros(0, dtype=complex) return calculate_unitary_big_endian(self.instructions, qubits)
@property def qubits_frozen(self) -> bool: """bool: Whether the circuit's qubits are frozen, that is, cannot be remapped. This may happen because the circuit contains compiler directives preventing compilation of a part of the circuit, which consequently means that none of the other qubits can be rewired either for the program to still make sense. """ return self._has_compiler_directives @property def observables_simultaneously_measurable(self) -> bool: """bool: Whether the circuit's observables are simultaneously measurable If this is False, then the circuit can only be run when shots = 0, as sampling (shots > 0) measures the circuit in the observables' shared eigenbasis. """ return self._observables_simultaneously_measurable def _encounter_noncommuting_observable(self) -> None: self._observables_simultaneously_measurable = False # No longer simultaneously measurable, so no need to track self._qubit_observable_mapping.clear() self._qubit_observable_target_mapping.clear() def _copy(self) -> Circuit: copy = Circuit().add(self.instructions) copy.add(self.result_types) return copy
[docs] def copy(self) -> Circuit: """ Return a shallow copy of the circuit. Returns: Circuit: A shallow copy of the circuit. """ return self._copy()
def __iadd__(self, addable: AddableTypes) -> Circuit: return self.add(addable) def __add__(self, addable: AddableTypes) -> Circuit: new = self._copy() new.add(addable) return new def __repr__(self) -> str: if not self.result_types: return f"Circuit('instructions': {self.instructions})" else: return ( f"Circuit('instructions': {self.instructions}" + f", 'result_types': {self.result_types})" ) def __str__(self): return self.diagram(AsciiCircuitDiagram) def __eq__(self, other): if isinstance(other, Circuit): return ( self.instructions == other.instructions and self.result_types == other.result_types ) return NotImplemented def __call__(self, arg: Any = None, **kwargs) -> Circuit: """ Implements the call function to easily make a bound Circuit. Args: arg (Any): A value to bind to all parameters. Defaults to None and can be overridden if the parameter is in kwargs. Returns: Circuit: A circuit with the specified parameters bound. """ param_values = dict() if arg is not None: for param in self.parameters: param_values[str(param)] = arg for key, val in kwargs.items(): param_values[str(key)] = val return self.make_bound_circuit(param_values)
[docs]def subroutine(register: bool = False) -> Callable: """ Subroutine is a function that returns instructions, result types, or circuits. Args: register (bool): If `True`, adds this subroutine into the `Circuit` class. Default = `False`. Returns: Callable: The subroutine function. Examples: >>> @circuit.subroutine(register=True) >>> def bell_circuit(): ... return Circuit().h(0).cnot(0, 1) ... >>> circ = Circuit().bell_circuit() >>> for instr in circ.instructions: ... print(instr) ... Instruction('operator': 'H', 'target': QubitSet(Qubit(0),)) Instruction('operator': 'H', 'target': QubitSet(Qubit(1),)) """ def _subroutine_function_wrapper(func: Callable[..., SubroutineReturn]) -> SubroutineReturn: if register: Circuit.register_subroutine(func) return func return _subroutine_function_wrapper