z itSrSSKJr SSKJrJrJr SSKJr SSK J r "SS\5r S S Sjjr g ) zPhase estimation circuit.) annotations)QuantumCircuitQuantumRegisterGate)deprecate_func)QFTc`^\rSrSrSr\"SSSS9S S U4Sjjj5rSrU=r$) PhaseEstimationuPhase Estimation circuit. In the Quantum Phase Estimation (QPE) algorithm [1, 2, 3], the Phase Estimation circuit is used to estimate the phase :math:`\phi` of an eigenvalue :math:`e^{2\pi i\phi}` of a unitary operator :math:`U`, provided with the corresponding eigenstate :math:`|\psi\rangle`. That is .. math:: U|\psi\rangle = e^{2\pi i\phi} |\psi\rangle This estimation (and thereby this circuit) is a central routine to several well-known algorithms, such as Shor's algorithm or Quantum Amplitude Estimation. References: [1] Kitaev, A. Y. (1995). Quantum measurements and the Abelian Stabilizer Problem. 1–22. `quant-ph/9511026 `_ [2] Michael A. Nielsen and Isaac L. Chuang. 2011. Quantum Computation and Quantum Information: 10th Anniversary Edition (10th ed.). Cambridge University Press, New York, NY, USA. [3] Qiskit `textbook `_ z2.1z4Use qiskit.circuit.library.phase_estimation instead.z in Qiskit 3.0)sinceadditional_msgremoval_timelinec >[US5n[URS5n[XVUS9nUc[USSS9R 5nUR U5 [ U5H;nURURSU-5R5U/USS-SS 9 M= URX5SSSS 9 [T U],"URS UR06 URUR5URSS 9 g) a Args: num_evaluation_qubits: The number of evaluation qubits. unitary: The unitary operation :math:`U` which will be repeated and controlled. iqft: A inverse Quantum Fourier Transform, per default the inverse of :class:`~qiskit.circuit.library.QFT` is used. Note that the QFT should not include the usual swaps! name: The name of the circuit. .. note:: The inverse QFT should not include a swap of the qubit order. Reference Circuit: .. plot:: :alt: Diagram illustrating the previously described circuit. from qiskit.circuit import QuantumCircuit from qiskit.circuit.library import PhaseEstimation from qiskit.visualization.library import _generate_circuit_library_visualization unitary = QuantumCircuit(2) unitary.x(0) unitary.y(1) circuit = PhaseEstimation(3, unitary) _generate_circuit_library_visualization(circuit) evalqnameNTF)inversedo_swapsqubitsinplacer)r num_qubitsrr reverse_bitshrangecomposepowercontrolsuper__init__qregsrto_gater) selfnum_evaluation_qubitsunitaryiqftrqr_evalqr_statecircuitj __class__s a/home/james-whalen/.local/lib/python3.13/site-packages/qiskit/circuit/library/phase_estimation.pyr"PhaseEstimation.__init__4sN""7@"7#5#5s; > <,dUKXXZD ',-A OOGMM!Q$/7791#QR BS]aO b. QZ> '--;gll; W__&t{{D I)NQPE) r&intr'rr(zQuantumCircuit | NonerstrreturnNone) __name__ __module__ __qualname____firstlineno____doc__rr"__static_attributes__ __classcell__)r-s@r.r r si:M('+ 1J"1J 1J$ 1J  1J  1J  1Jr0r cSSKJnJn [US5n[URS5n[ XVUS9nUR U5 [U5H;nURURSU-5R5U/USS-SS 9 M= URU"U5R5USS5 [[[U555n URU"U 5USS5 U$) uPhase Estimation circuit. In the Quantum Phase Estimation (QPE) algorithm [1, 2, 3], the Phase Estimation circuit is used to estimate the phase :math:`\phi` of an eigenvalue :math:`e^{2\pi i\phi}` of a unitary operator :math:`U`, provided with the corresponding eigenstate :math:`|\psi\rangle`. That is .. math:: U|\psi\rangle = e^{2\pi i\phi} |\psi\rangle This estimation (and thereby this circuit) is a central routine to several well-known algorithms, such as Shor's algorithm or Quantum Amplitude Estimation. Args: num_evaluation_qubits: The number of evaluation qubits. unitary: The unitary operation :math:`U` which will be repeated and controlled. This can either be a :class:`.QuantumCircuit` or a :class:`.Gate`. Passing gates can often be more performant, as it allows calling optimized control and power subroutines. name: The name of the output circuit. Reference Circuit: .. plot:: :alt: A phase estimation circuit. :include-source: from qiskit.circuit.library import phase_estimation, PauliEvolutionGate from qiskit.quantum_info import SparsePauliOp hamiltonian = SparsePauliOp(["ZZ", "IX", "XI"]) evo = PauliEvolutionGate(hamiltonian, time=0.1) # implements exp(-itH) circuit = phase_estimation(3, evo) # QPE for the evolution operator circuit.draw("mpl") References: [1] Kitaev, A. Y. (1995). Quantum measurements and the Abelian Stabilizer Problem. 1–22. `quant-ph/9511026 `_ [2] Michael A. Nielsen and Isaac L. Chuang. 2011. Quantum Computation and Quantum Information: 10th Anniversary Edition (10th ed.). Cambridge University Press, New York, NY, USA. [3] Qiskit `textbook `_ r)PermutationGateQFTGaterrrrNTr)qiskit.circuit.libraryr?r@rrrrrrrr appendrlistreversed) r&r'rr?r@r)r*r+r,reversal_patterns r.phase_estimationrFmsn@3VOY]^* NN70199;WQZHHU+@%ABC NN?#34gajA Nr0N)r2)r&r3r'zQuantumCircuit | Gaterr4r5r) r; __future__rqiskit.circuitrrrqiskit.utils.deprecationrrArr rFr1r0r.rJs] "@@3&TJnTJtGG "G G Gr0