  In this paper we present two new classes of binary quantum codes with minimum
distance of at least three, by self-complementary self-dual orientable
embeddings of voltage graphs and Paley graphs in the Galois field GF(pr), where
p is a prime number and r is a positive integer. The parameters of two new
classes of quantum codes are [[(2k+2)(8k+ 7); 2(8k^2+7k); d]] and
[[(2k+2)(8k+9); 2(8k^2+9k+1); d]] respectively, where d>=3. For these quantum
codes, the code rate approaches 1 as k goes to infinity.
