Southwest Quantum Information and Technology

Advances in surface code quantum computation

Presenting Author: Benjamin Brown, University of Sydney

The surface code has emerged as one of the leading candidate quantum error-correcting codes to maintain the logical qubits of the first generation of scalable quantum computers. In this talk I will summarise my recent results that may alleviate some of the issues towards the development of a quantum computer based on a surface code architecture. I will first discuss work showing how to complete a universal set of fault-tolerant logical gates with the surface code without the need for distillation methods. This includes work showing how we can braid Majorana modes lying at the corners of the planar code to realise Clifford operations. I will also explain how the surface code can be connected to its three-dimensional generalisation to realise a non-Clifford gate using a two-dimensional system. Both of these proposals offer new routes to reduce the resource cost of scalable quantum computation as they circumvent the need for conventional distillation methods to complete a universal set of logic gates. Finally, I will briefly mention new results where we show that we can increase the threshold of a tailored variant of the surface code by specialising the decoder to deal with the common situation where the noise each qubit experiences is biased towards dephasing. This development means that the surface code can tolerate a higher rate of noise such that it is more readily constructed in the laboratory with modern hardware.

(Session 12 : Monday from 1:15pm - 2:00pm)