Tailoring Quantum Error Correcting Protocols to Biased Noise Models

Abstract

Quantum systems are inherently vulnerable to asymmetric noise processes which manifest as biased noise channels in quantum computing systems. To mitigate the effects of these noise mechanisms efficiently, quantum error correction (QEC) protocols can be tailored to prioritize the suppression of these dominant errors. In this dissertation, we characterize the benefits of noise-tailoring methods by evaluating their qualitative effects on the structure of QEC codes and performing a comparative analysis of the thresholds and logical error rates between tailored and standard codes. In particular, the utility of Clifford deformations are explored in both the circuit-based and measurement-based quantum computing frameworks. The primary strength of this technique lies in its ability to introduce additional symmetries to the stabilizers of a QEC protocol. These symmetries make the code more perceptive to dominant errors while providing the decoder with information on the underlying structures of syndrome configurations, thereby enabling more accurate decoding. Despite the trade-offs that often come with these modifications, our results demonstrate gains in error tolerance thresholds and more efficient suppression of logical error rates. The methodologies and perspectives presented in this work can provide guidance for designing and optimizing QEC protocols tailored to biased noise models.