  According to the Gottesman-Knill theorem, a class of quantum circuits, namely
the so-called stabilizer circuits, can be simulated efficiently on a classical
computer. We introduce a new algorithm for this task, which is based on the
graph-state formalism. It shows significant improvement in comparison to an
existing algorithm, given by Gottesman and Aaronson, in terms of speed and of
the number of qubits the simulator can handle. We also present an
implementation.
