Riverlane Ltd.

Ben Andrew Barber

Kenton Michael Barnes

Kauser Yakub Johar

Luka Skoric

Jacob M Taylor

Neil Ian Gillespie

A computer-implemented method for use in decoding syndromes of a quantum error correction code, the syndromes comprising measurement data from a quantum computer comprising a plurality of syndrome qubits and a plurality of data qubits. The method comprises: processing the syndromes to identify defects; recording, in a data structure, respective locations for each defect; and determining a respective radius, for each respective defect, of a ball surrounding the respective location of the respective defect, and recording each respective radius with its respective location in the data structure, wherein each respective radius is determined by iteratively increasing a length of the respective radius until each respective radius defines a ball touching or overlapping at least one other ball surrounding another of the respective locations, such that each respective location belongs to a cluster consisting of an even number of the locations of the defects; wherein the data structure thereby enables decoding of the quantum error correction code.

Decoding quantum error correction codes

A decoder apparatus for decoding syndromes of a quantum error correction code, the syndromes comprising measurement data from a quantum computer, the quantum computer comprising an array of qubits including syndrome qubits and data qubits. The decoder apparatus is configured to: receive syndrome index data representative of: a physical location of each of the array of qubits within the quantum computer; and lattice dimensions of the array of qubits; receive the syndromes of the quantum error correction code from the quantum computer; determine physical co-ordinate positions for each of the array of qubits based on the syndrome index data; decode the syndromes of the quantum error correction code using the determined physical co-ordinate positions. The decoder apparatus has a first syndrome capacity for decoding quantum error correction code syndromes and the syndromes of the quantum error correction code occupy a second syndrome capacity less than or equal to the first syndrome capacity of the decoder apparatus.

Quantum error correction code decoder and associated methods

A computer-implemented postselection-free method of initializing qubits in a quantum computer, comprising: preparing at least one data qubit and a plurality of auxiliary qubits in respective initial states, wherein each of the at least one data qubit and the plurality of auxiliary qubits has a respective probability of being prepared with an error; and, performing a plurality of non-measurement multi-qubit quantum logic operations that propagate errors between the at least one data qubit and the plurality of auxiliary qubits so as to reduce the probability of an error affecting the at least one data qubit.

Growing community of inventors

Cambridge, United Kingdom

Ben Andrew Barber