# xGate

Pauli X gate

Since R2023a

Installation Required: This functionality requires MATLAB Support Package for Quantum Computing.

## Syntax

``g = xGate(targetQubit)``

## Description

example

````g = xGate(targetQubit)` applies a Pauli X gate to a single target qubit and returns a `quantum.gate.SimpleGate` object.If `targetQubit` is a vector of qubit indices, `xGate` returns a column vector of gates, where `g(i)` represents a Pauli X gate applied to a qubit with index `targetQubit(i)`.```

## Examples

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Create a Pauli X gate that acts on a single qubit.

`g = xGate(1)`
```g = SimpleGate with properties: Type: "x" ControlQubits: [1×0 double] TargetQubits: 1 Angles: [1×0 double]```

Get the matrix representation of the gate.

`M = getMatrix(g)`
```M = 0 1 1 0```

Create an array of Pauli X gates that act on qubits with indices 1 to 4.

`g = xGate(1:4)`
```g = 4×1 SimpleGate array with gates: Id Gate Control Target 1 x 1 2 x 2 3 x 3 4 x 4 ```

## Input Arguments

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Target qubit of the gate, specified as a positive integer scalar index or vector of qubit indices.

Example: `1`

Example: `3:5`

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### Matrix Representation of Pauli X Gate

The matrix representation of a Pauli X gate applied to a single qubit is

`$\left[\begin{array}{cc}0& 1\\ 1& 0\end{array}\right].$`

This gate maps the $|0〉$ state to the $|1〉$ state and maps the $|1〉$ state to the $|0〉$ state. This gate is also known as a bit-flip gate and is the quantum equivalent of the classical NOT gate.

## Version History

Introduced in R2023a