U2Gate

class qiskit.circuit.library.U2Gate(phi, lam, label=None)

Bases: Gate

Single-qubit rotation about the X+Z axis.

Implemented using one X90 pulse on IBM Quantum systems:

Warning

This gate is deprecated. Instead, the following replacements should be used

U2(\phi, \lambda) = U\left(\frac{\pi}{2}, \phi, \lambda\right)

circuit = QuantumCircuit(1)
circuit.u(pi/2, phi, lambda)

Circuit symbol:

     ┌─────────┐
q_0: ┤ U2(φ,λ) ├
     └─────────┘

Matrix Representation:

\begin{split}U2(\phi, \lambda) = \frac{1}{\sqrt{2}} \begin{pmatrix} 1 & -e^{i\lambda} \\ e^{i\phi} & e^{i(\phi+\lambda)} \end{pmatrix}\end{split}

Examples:

U2(\phi,\lambda) = e^{i \frac{\phi + \lambda}{2}}RZ(\phi) RY\left(\frac{\pi}{2}\right) RZ(\lambda) = e^{- i\frac{\pi}{4}} P\left(\frac{\pi}{2} + \phi\right) \sqrt{X} P\left(\lambda- \frac{\pi}{2}\right)

U2(0, \pi) = H

U2(0, 0) = RY(\pi/2)

U2(-\pi/2, \pi/2) = RX(\pi/2)

Attributes

Get Clbits in condition.

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

Return definition in terms of other basic gates.

Get the duration.

Return instruction label

Return the name.

Return the number of clbits.

Return the number of qubits.

return instruction params.

Get the time unit of duration.

inverse()

Return inverted U2 gate.

$U2(\phi, \lambda)^{\dagger} =U2(-\lambda-\pi, -\phi+\pi)$ )

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