PhD student Michael Vasmer wins best poster prize at QEC19

PhD student Michael Vasmer has won the first prize for his poster presented at the Fifth International Conference on Quantum Error Correction (QEC19) held this week at the Senate House in London. Michael’s poster was about a cellular automaton decoder for quantum error-correcting codes. Cellular automata such as Conway's Game of Life are models which consist of cells following simple local update rules. These models exhibit complex emergent behaviour and have been studied across the sciences. He uses quantum error-correcting codes to protect quantum information from errors caused by environmental noise and imperfect control. In practice, he measures certain check operators (defined by the code) which give us incomplete information about the errors that have occurred. However, there is a need to process this information using a classical algorithm before the error can be corrected. Such an algorithm is called a decoder. Cellular automata are good candidate decoders because their simple update rules mean that they can correct errors very fast. He proposes and benchmarks (using simulations) a decoder based on a cellular automaton called the Sweep Rule. His decoder works for a wide variety of topological quantum codes, and he found that it can be used to decode a family of topological codes called 3D surface codes as long as the error rate per component is lower than 1.7%. This work was carried out in collaboration with Dan Browne, his supervisor at UCL, and Alex Kubica, a postdoctoral research fellow at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.