Towards fault-tolerant quantum computing through the lens of quantum memory

Given the fundamental physical challenges in quantum computing that result in frequent and unavoidable errors, significant efforts are put into fault-tolerant quantum computing architectures enabling the execution of complex, long-running, error-free computations. At its core, Quantum Error Correction (QEC) going beyond traditional error mitigation has been introduced to address the high error rates. There is a wide range of error sources including bit or phase flips, noise, leakage, gate errors, hardware imperfections, as well as initialization or measurements errors. From a quantum memory perspective, errors can happen on idle data or check qubits. They need to be detected and corrected while instructions are being executed.

In this talk we analyze major similarities and disparities from error correction in traditional storage and memory devices and give an overview of state-of-the art QEC algorithms with a focus on a family of low-density parity-check codes. For these codes, about an order of magnitude more physical qubits are required than logical ones. Finally, we give an overview of the tools and infrastructure needed to evaluate the performance of such codes.