Triangle Quantum Computing Seminar Series: A fault-tolerant quantum computer based on bivariate bicycle codes

Abstract: Last year, we debuted the bicycle architecture [1], a modular quantum computing framework which performs universal, fault-tolerant quantum computation on information encoded into bivariate bicycle codes. As a first of its kind quantum computer employing high-rate, low-density parity-check (LDPC) codes and generalized code surgery, we anticipated the blueprint to evolve based on further research. Here, I will review the design principles and advantages of the bicycle architecture, including its low qubit overhead and flexibility, and present updates, including some new benchmarking results in the low-error regime [2]. In parallel, IBM is excited to be making quantum LDPC codes a reality in superconducting hardware, and I will present some updates from that effort. [1] Theodore J. Yoder, Eddie Schoute, Patrick Rall, Emily Pritchett, Jay M. Gambetta, Andrew W. Cross, Malcolm Carroll, and Michael E. Beverland. Tour de gross: A modular quantum computer based on bivariate bicycle codes. https://arxiv.org/pdf/2506.03094. [2] Michael E. Beverland, Malcolm Carroll, Andrew W. Cross, Theodore J. Yoder. Fail fast: techniques to probe rare events in quantum error correction. https://arxiv.org/abs/2511.15177. Bio: Since obtaining his PhD from MIT in 2018, Ted has been a research scientist at IBM working largely on the theory of quantum error-correction. Of late, he is especially interested in the direction of quantum LDPC codes and in making their practical implementation a reality. --- Co-hosted by the Duke Quantum Center, the NC State Quantum Initiative, and the UNC Kenan-Flagler's Rethinc. Labs.