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ZGate

class ZGate(label=None)

GitHub

Bases: qiskit.circuit.gate.Gate

The single-qubit Pauli-Z gate (σz\sigma_z).

Matrix Representation:

Z=(100−1)\begin{split}Z = \begin{pmatrix} 1 & 0 \\ 0 & -1 \end{pmatrix}\end{split}

Circuit symbol:

     ┌───┐
q_0: ┤ Z ├
     └───┘

Equivalent to a π\pi radian rotation about the Z axis.

Note

A global phase difference exists between the definitions of RZ(π)RZ(\pi) and ZZ.

RZ(π)=(−1001)=−Z\begin{split}RZ(\pi) = \begin{pmatrix} -1 & 0 \\ 0 & 1 \end{pmatrix} = -Z\end{split}

The gate is equivalent to a phase flip.

∣0⟩→∣0⟩∣1⟩→−∣1⟩\begin{split}|0\rangle \rightarrow |0\rangle \\ |1\rangle \rightarrow -|1\rangle\end{split}

Create new Z gate.

Methods Defined Here

control

ZGate.control(num_ctrl_qubits=1, label=None, ctrl_state=None)

Return a (multi-)controlled-Z gate.

One control returns a CZ gate.

Parameters

  • num_ctrl_qubits (int) – number of control qubits.
  • label (str or None) – An optional label for the gate [Default: None]
  • ctrl_state (int or str or None) – control state expressed as integer, string (e.g. ‘110’), or None. If None, use all 1s.

Returns

controlled version of this gate.

Return type

ControlledGate

inverse

ZGate.inverse()

Return inverted Z gate (itself).

Attributes

condition_bits

Get Clbits in condition.

Return type

List[Clbit]

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

Return type

str

params

return instruction params.

unit

Get the time unit of duration.

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