An apparatus for mitigating loss of fidelity of coded entangled qubit states stored in a memory system comprising: a register configured to store a coded entangled qubit state generated using a quantum stabilizer code; a measurement circuit configured to perform a redundant measurement of a set of syndrome values corresponding to the coded entangled qubit state, wherein the redundant measurement determines a sub-vector (v sub) of a vector (v), components of the vector (v) being the binary components of a syndrome vector and parity bits of the syndrome vector, the components of the syndrome vector being the syndrome values corresponding to the coded entangled qubit state, the determined sub-vector (v sub) having a subset of the syndrome values of the syndrome vector as first components thereof and the parity bits as second components thereof, the vector (v) being a codeword of a block error-correction code; an erasure-value generator configured to generate a set of binary erasure values for initializing the remaining binary components of the syndrome vector not determined by the redundant measurement; and a decoder configured to determine a probable syndrome vector corresponding to the coded entangled qubit state using a bipartite graph corresponding to the block error-correction code and the sub-vector (v sub) determined by the redundant measurement of the set of syndrome values, and the decoder being further configured to apply the set of erasure values generated by the erasure-value generator to initialize a set of variable nodes of the bipartite graph not configured to receive a measured syndrome value from the measurement circuit. a register configured to store a coded entangled qubit state generated using a quantum stabilizer code; a measurement circuit configured to perform a redundant measurement of a set of syndrome values corresponding to the coded entangled qubit state, wherein the redundant measurement determines a sub-vector (v sub) of a vector (v), components of the vector (v) being the binary components of a syndrome vector and parity bits of the syndrome vector, the components of the syndrome vector being the syndrome values corresponding to the coded entangled qubit state, the determined sub-vector (v sub) having a subset of the syndrome values of the syndrome vector as first components thereof and the parity bits as second components thereof, the vector (v) being a codeword of a block error-correction code; an erasure-value generator configured to generate a set of binary erasure values for initializing the remaining binary components of the syndrome vector not determined by the redundant measurement; and a decoder configured to determine a probable syndrome vector corresponding to the coded entangled qubit state using a bipartite graph corresponding to the block error-correction code and the sub-vector (v sub) determined by the redundant measurement of the set of syndrome values, and the decoder being further configured to apply the set of erasure values generated by the erasure-value generator to initialize a set of variable nodes of the bipartite graph not configured to receive a measured syndrome value from the measurement circuit.