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PhaseGate

class qiskit.circuit.library.PhaseGate(theta, label=None)

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Bases: Gate

Single-qubit rotation about the Z axis.

This is a diagonal gate. It can be implemented virtually in hardware via framechanges (i.e. at zero error and duration).

Can be applied to a QuantumCircuit with the p() method.

Circuit symbol:

     ┌──────┐
q_0:P(λ)
     └──────┘

Matrix Representation:

P(λ)=(100eiλ)\begin{split}P(\lambda) = \begin{pmatrix} 1 & 0 \\ 0 & e^{i\lambda} \end{pmatrix}\end{split}

Examples:

P(λ=π)=ZP(\lambda = \pi) = Z P(λ=π/2)=SP(\lambda = \pi/2) = S P(λ=π/4)=TP(\lambda = \pi/4) = T
See also

RZGate: This gate is equivalent to RZ up to a phase factor.

P(λ)=eiλ/2RZ(λ)P(\lambda) = e^{i{\lambda}/2} RZ(\lambda)

Reference for virtual Z gate implementation: 1612.00858

Create new Phase gate.


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

control

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

Return a (multi-)controlled-Phase 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 orstr 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

inverse()

Return inverted Phase gate (Phase(λ)=Phase(λ)Phase(\lambda)^{\dagger} = Phase(-\lambda))

power

power(exponent)

Raise gate to a power.

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