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XXPlusYYGate

class qiskit.circuit.library.XXPlusYYGate(theta, beta=0, label='(XX+YY)')

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Bases: Gate

XX+YY interaction gate.

A 2-qubit parameterized XX+YY interaction, also known as an XY gate. Its action is to induce a coherent rotation by some angle between ∣01⟩|01\rangle and ∣10⟩|10\rangle.

Circuit Symbol:

     ┌───────────────┐
q_0: ┤0              ├
     │  (XX+YY)(θ,β) │
q_1: ┤1              ├
     └───────────────┘

Matrix Representation:

RXX+YY(θ,β) q0,q1=RZ0(−β)⋅exp⁡(−iθ2XX+YY2)⋅RZ0(β)=(10000cos⁡(θ2)−isin⁡(θ2)e−iβ00−isin⁡(θ2)eiβcos⁡(θ2)00001)\providecommand{\th}{\frac{\theta}{2}}\\\begin{split}R_{XX+YY}(\theta, \beta)\ q_0, q_1 = RZ_0(-\beta) \cdot \exp\left(-i \frac{\theta}{2} \frac{XX+YY}{2}\right) \cdot RZ_0(\beta) = \begin{pmatrix} 1 & 0 & 0 & 0 \\ 0 & \cos\left(\th\right) & -i\sin\left(\th\right)e^{-i\beta} & 0 \\ 0 & -i\sin\left(\th\right)e^{i\beta} & \cos\left(\th\right) & 0 \\ 0 & 0 & 0 & 1 \end{pmatrix}\end{split}
Note

In Qiskit’s convention, higher qubit indices are more significant (little endian convention). In the above example we apply the gate on (q_0, q_1) which results in adding the (optional) phase defined by betabeta on q_0. Instead, if we apply it on (q_1, q_0), the phase is added on q_1. If betabeta is set to its default value of 00, the gate is equivalent in big and little endian.

     ┌───────────────┐
q_0: ┤1              ├
     │  (XX+YY)(θ,β) │
q_1: ┤0              ├
     └───────────────┘
RXX+YY(θ,β) q0,q1=RZ1(−β)⋅exp⁡(−iθ2XX+YY2)⋅RZ1(β)=(10000cos⁡(θ2)−isin⁡(θ2)eiβ00−isin⁡(θ2)e−iβcos⁡(θ2)00001)\providecommand{\th}{\frac{\theta}{2}}\\\begin{split}R_{XX+YY}(\theta, \beta)\ q_0, q_1 = RZ_1(-\beta) \cdot \exp\left(-i \frac{\theta}{2} \frac{XX+YY}{2}\right) \cdot RZ_1(\beta) = \begin{pmatrix} 1 & 0 & 0 & 0 \\ 0 & \cos\left(\th\right) & -i\sin\left(\th\right)e^{i\beta} & 0 \\ 0 & -i\sin\left(\th\right)e^{-i\beta} & \cos\left(\th\right) & 0 \\ 0 & 0 & 0 & 1 \end{pmatrix}\end{split}

Create new XX+YY gate.

Parameters

Attributes

condition_bits

Get Clbits in condition.

decompositions

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

definition

Return definition in terms of other basic gates.

duration

Get the duration.

label

Return instruction label

name

Return the name.

num_clbits

Return the number of clbits.

num_qubits

Return the number of qubits.

params

return instruction params.

unit

Get the time unit of duration.

Methods

inverse

inverse()

Return inverse XX+YY gate (i.e. with the negative rotation angle and same phase angle).

power

power(exponent)

Raise gate to a power.

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