HRSCumulativeMultiplier¶
- class HRSCumulativeMultiplier(num_state_qubits, num_result_qubits=None, adder=None, name='HRSCumulativeMultiplier')[source]¶
Bases:
qiskit.circuit.library.arithmetic.multipliers.multiplier.Multiplier
A multiplication circuit to store product of two input registers out-of-place.
Circuit uses the approach from [1]. As an example, a multiplier circuit that performs a non-modular multiplication on two 3-qubit sized registers with the default adder is as follows (where
Adder
denotes theCDKMRippleCarryAdder
):a_0: ────■───────────────────────── │ a_1: ────┼─────────■─────────────── │ │ a_2: ────┼─────────┼─────────■───── ┌───┴────┐┌───┴────┐┌───┴────┐ b_0: ┤0 ├┤0 ├┤0 ├ │ ││ ││ │ b_1: ┤1 ├┤1 ├┤1 ├ │ ││ ││ │ b_2: ┤2 ├┤2 ├┤2 ├ │ ││ ││ │ out_0: ┤3 ├┤ ├┤ ├ │ ││ ││ │ out_1: ┤4 ├┤3 ├┤ ├ │ Adder ││ Adder ││ Adder │ out_2: ┤5 ├┤4 ├┤3 ├ │ ││ ││ │ out_3: ┤6 ├┤5 ├┤4 ├ │ ││ ││ │ out_4: ┤ ├┤6 ├┤5 ├ │ ││ ││ │ out_5: ┤ ├┤ ├┤6 ├ │ ││ ││ │ aux_0: ┤7 ├┤7 ├┤7 ├ └────────┘└────────┘└────────┘
Multiplication in this circuit is implemented in a classical approach by performing a series of shifted additions using one of the input registers while the qubits from the other input register act as control qubits for the adders.
References:
[1] Häner et al., Optimizing Quantum Circuits for Arithmetic, 2018. arXiv:1805.12445
- Parameters
num_state_qubits (
int
) – The number of qubits in either input register for state \(|a\rangle\) or \(|b\rangle\). The two input registers must have the same number of qubits.num_result_qubits (
Optional
[int
]) – The number of result qubits to limit the output to. If number of result qubits is \(n\), multiplication modulo \(2^n\) is performed to limit the output to the specified number of qubits. Default value is2 * num_state_qubits
to represent any possible result from the multiplication of the two inputs.adder (
Optional
[QuantumCircuit
]) – Half adder circuit to be used for performing multiplication. The CDKMRippleCarryAdder is used as default if no adder is provided.name (
str
) – The name of the circuit object.
- Raises
NotImplementedError – If
num_result_qubits
is not default and a custom adder is provided.
Attributes
- ancillas¶
Returns a list of ancilla bits in the order that the registers were added.
- Return type
List
[AncillaQubit
]
- calibrations¶
Return calibration dictionary.
- The custom pulse definition of a given gate is of the form
{‘gate_name’: {(qubits, params): schedule}}
- Return type
dict
- clbits¶
Returns a list of classical bits in the order that the registers were added.
- Return type
List
[Clbit
]
- data¶
Return the circuit data (instructions and context).
- Returns
a list-like object containing the tuples for the circuit’s data.
Each tuple is in the format
(instruction, qargs, cargs)
, where instruction is an Instruction (or subclass) object, qargs is a list of Qubit objects, and cargs is a list of Clbit objects.- Return type
QuantumCircuitData
- extension_lib = 'include "qelib1.inc";'¶
- global_phase¶
Return the global phase of the circuit in radians.
- Return type
Union
[ParameterExpression
,float
]
- header = 'OPENQASM 2.0;'¶
- instances = 9¶
- metadata¶
The user provided metadata associated with the circuit
The metadata for the circuit is a user provided
dict
of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.- Return type
dict
- num_ancillas¶
Return the number of ancilla qubits.
- Return type
int
- num_clbits¶
Return number of classical bits.
- Return type
int
- num_parameters¶
Convenience function to get the number of parameter objects in the circuit.
- Return type
int
- num_qubits¶
Return number of qubits.
- Return type
int
- num_result_qubits¶
The number of result qubits to limit the output to.
- Return type
int
- Returns
The number of result qubits.
- num_state_qubits¶
The number of state qubits, i.e. the number of bits in each input register.
- Return type
int
- Returns
The number of state qubits.
- parameters¶
Convenience function to get the parameters defined in the parameter table.
- Return type
ParameterView
- prefix = 'circuit'¶