Decoding algorithms for quantum error correcting codes

Laburpena

Quantum computers would prove a ground-breaking effect in several re- search fields to the advantage of our society due to their proved capacity for solving some problems deemed as too complex for classical comput- ers. Consequently, there is a generalized academic effort for constructing a quantum computer. Nonetheless, a real quantum computer does not suffice for implementing quantum algorithms reliably, it must be fault-tolerant. Quantum computers undergo noise due to a phenomenon generally named quantum decoherence, a fault-tolerant quantum computer has the capabil- ity to suppress the effects of decoherence to an extent. For that to happen, a quantum computer should consider quantum error correction, a process in which decoherence is studied and attempted to be corrected. Within the context of quantum error correction, the information from quantum proces- sors is to be stored in a larger, more redundant system named a quantum error correcting code. Afterwards, one can obtain a vector named syndrome which provides partial information on the effect decoherence has had on a code. The process of recovering the decoherence or error that the code has undergone is named decoding. This thesis studies decoders for quan- tum error correcting codes, their performance, complexity and adaption to different types of quantum decoherence.