- #1

- 1,030

- 4

## Main Question or Discussion Point

I'm not sure where to post this, so here it is:

[tex]\left[\begin{array}{cccc}

1&0&0&0\\

0&1&0&0\\

0&0&0&1\\

0&0&1&0\\

\end{array}\right][/tex]

How is this a controlled NOT gate? If I multiply this with [tex]\left[\begin{array}{c}1\\0\\1\\0\end{array}\right][/tex], the second bit is flipped regardless.

[tex]\left[\begin{array}{cccc}

1&0&0&0\\

0&1&0&0\\

0&0&0&1\\

0&0&1&0\\

\end{array}\right][/tex]

How is this a controlled NOT gate? If I multiply this with [tex]\left[\begin{array}{c}1\\0\\1\\0\end{array}\right][/tex], the second bit is flipped regardless.