A decoherent limit of fault-tolerant quantum computation driven by coherent fields
Li Yang, Yufu Chen · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
Based on amplitude character of quantum Rabi oscillation driven by coherent field we show that there exists an upper bound to logic complexity of quantum circuit. We introduce a parameter called single-qubit logic complexity and estimate its decoherence limit in a reasonable case. The analysis show that a generally accepted constant threshold of the threshold theorem limits the logic complexity to so small a number that even a typical construction of fault-tolerant quantum Toffoli gate can hardly be implemented reliably. This result suggests that the construction of feasible fault-tolerant quantum gates is still an arduous task.