Asymptotically good quantum codes exceeding the Ashikhmin-Litsyn-Tsfasman bound

It is known that quantum error correction can be achieved using classical binary codes or additive codes over F4 (see [2], [3], [9]). In [1] and [4], asymptotically good quantum codes from algebraic-geometry codes were constructed and, in [1], a bound on on (δ, R) was computed from the Tsfasman-Vladut-Zink bound of the theory of classical algebraic-geometry codes. In this correspondence, by the use of a concatenation technique we construct a family of asymptotically good quantum codes exceeding the bound in a small interval.Accepted versio