Steane code

The Steane code is a tool in quantum error correction introduced by Andrew Steane in 1996. It is a CSS code (Calderbank-Shor-Steane), using the classical binary [7,4,3] Hamming code to correct for both qubit flip errors (X errors) and phase flip errors (Z errors). The Steane code encodes one logical qubit in 7 physical qubits and is able to correct arbitrary single qubit errors.

Its check matrix in standard form is

${\displaystyle {\begin{bmatrix}H&0\\0&H\end{bmatrix}}}$

where H is the parity-check matrix of the Hamming code and is given by

${\displaystyle H={\begin{bmatrix}1&0&0&1&0&1&1\\0&1&0&1&1&0&1\\0&0&1&0&1&1&1\end{bmatrix}}.}$

The ${\displaystyle [[7,1,3]]}$ Steane code is the first in the family of quantum Hamming codes, codes with parameters ${\displaystyle [[2^{r}-1,2^{r}-1-2r,3]]}$ for integers ${\displaystyle r\geq 3}$. It is also a quantum color code.