  Quantum low-density parity-check (qLDPC) codes are quantum stabilizer codes
where each stabilizer acts on a constant number of qubits and each qubit is
acted on by a constant number of stabilizers. We study qLDPC codes constructed
from balanced products and lossless expanders. We found that assuming the
existence of 2-sided lossless expander graphs with free group action, the
resulting qLDPC codes have constant rate, linear distance, and linear time
decoders.
