Good quantum LDPC codes and how to decode them


Gu, S.(. (2023). Good quantum LDPC codes and how to decode them. Perimeter Institute. https://pirsa.org/23120045


Gu, Shouzhen (Bailey). Good quantum LDPC codes and how to decode them. Perimeter Institute, Dec. 13, 2023, https://pirsa.org/23120045


          @misc{ pirsa_PIRSA:23120045,
            doi = {10.48660/23120045},
            url = {https://pirsa.org/23120045},
            author = {Gu, Shouzhen (Bailey)},
            keywords = {Quantum Information},
            language = {en},
            title = {Good quantum LDPC codes and how to decode them},
            publisher = {Perimeter Institute},
            year = {2023},
            month = {dec},
            note = {PIRSA:23120045 see, \url{https://pirsa.org}}

Shouzhen (Bailey) Gu California Institute of Technology (Caltech)


The last few years have seen rapid progress in the development of quantum low-density parity-check (LDPC) codes. LDPC codes, defined by their constant weight check operators, can have much better parameters than their topological counterparts like the surface code. In particular, a series of pivotal works culminated in the discovery of asymptotically good LDPC codes--those with essentially optimal rate and distance scalings. These codes allow for the possibility fault-tolerant quantum computation with very low overhead. However, for a code to be used in practice, it is necessary to efficiently identify errors from measurement outcomes to get back into the codespace. In this talk, I will present a linear-time decoder for a family of asymptotically good codes called quantum Tanner codes. Furthermore, I will show that quantum Tanner codes support single-shot decoding, which means that one measurement round suffices to perform reliable quantum error correction, even in the presence of measurement errors. These results can be seen as a step toward making quantum LDPC codes more practical.


Zoom link https://pitp.zoom.us/j/94286584094?pwd=Q21IekhHZXI4Qlk4Y1B3MnNobmR6UT09