We generalize a construction of non-binary quantum LDPC codes over \F_{2^m}
due to \cite{KHIS11a} and apply it in particular to toric codes. We obtain in
this way not only codes with better rates than toric codes but also improve
dramatically the performance of standard iterative decoding. Moreover, the new
codes obtained in this fashion inherit the distance properties of the
underlying toric codes and have therefore a minimum distance which grows as the
square root of the length of the code for fixed m.Comment: 9 pages, 9 figures, full version of a paper submitted to the IEEE
Symposium on Information Theor