Source code for mimiqcircuits.operations.gates.generalized.qft

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import mimiqcircuits.operations.gates.gate as mcg
from mimiqcircuits.operations.gates.standard.cphase import GateCP
from mimiqcircuits.operations.gates.standard.hadamard import GateH
import mimiqcircuits.lazy as lz
from symengine import pi


[docs] class QFT(mcg.Gate): """ Quantum Fourier transform. Performs the quantum Fourier transform on a register of `n` qubits. Args: n (int): The number of qubits in the quantum register. Raises: ValueError: If the number of qubits is less than 1. Returns: QFT: The Quantum Fourier Transform operation. Attributes: name (str): The name of the operation. num_qubits (int): The number of qubits in the quantum register. qregsizes (list of int): The sizes of the quantum registers. Examples: >>> from mimiqcircuits import * >>> c=Circuit() >>> c.push(QFT(2),1,2) 3-qubit circuit with 1 instructions: └── QFT @ q[1,2] <BLANKLINE> """ _name = "QFT" _num_qregs = 1 _num_qubits = None def __init__(self, num_qubits): if num_qubits < 1: raise ValueError("Number of qubits must be greater than 0") super().__init__() self._num_qubits = num_qubits self._qregsizes = [num_qubits] self._params = [num_qubits] def __new__(cls, *args): if len(args) == 0: return lz.LazyExpr(QFT, lz.LazyArg()) elif len(args) == 1: return object.__new__(cls) else: raise ValueError("Invalid number of arguments.") def _matrix(self): raise NotImplementedError( "Matrix representation for Quantum Fourier Transform is not implemented.") def _decompose(self, circ, qubits, bits): q = qubits[::-1] circ.push(GateH(), q[0]) for i in range(1, self.num_qubits): for j in range(i): angle = pi / (2.0**(i-j)) circ.push(GateCP(angle), q[i], q[j]) circ.push(GateH(), q[i]) return circ
__all__ = ['QFT']