Department of Physics & Astronomy
University of New Mexico

CQuIC Seminars

Performance of quantum error correction with coherent errors

Presented by Andrew Doherty, University of Sydney

A lot of recent studies have emphasized the need to better understand the effect of unitary errors on quantum computing. Specifically, randomized benchmarking, which roughly measures the average fidelity error, may underestimate the impact of unitary errors. This is because fault tolerance thresholds are typically expressed in terms of better behaved error metrics such as the diamond norm, and unitary errors can appear much larger when measured in this way.



This has motivated us to look carefully at the performance of error correction when errors are unitary. We study the effective error after ideal correction for a range of error correcting codes, and also obtain bounds that apply to all stabiliser codes. Broadly speaking, when errors are measured in terms of the diamond norm, we find that the error correction is typically much more effective for unitary errors than for dephasing. For certain codes this effect can be so large that the average fidelity error at the physical level is a good predictor of the error after correction for any combination of dephasing and unitary errors.

3:30 pm, Thursday, May 9, 2019
PAIS-2540, PAIS

Disability NoticeIndividuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact the Physics Department (phone: 505-277-2616, email: physics@unm.edu) well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact the Physics front office if you need written information in an alternative format.

A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at http://physics.unm.edu/pandaweb/events/index.php