Abstract: A quantum computing system includes a classical computer coupled in combination with a quantum computer, wherein the quantum computing system is configurable to execute program instructions to process input data to generate corresponding output data. The program instructions include one or more arithmetic functions to be executed using the quantum computer. The quantum computing system is configured to apply a transformation to transform the one or more arithmetic functions into a series of Fourier components that are executable using the quantum computer by using one or more quantum circuits utilizing rotation gates acting on qubits representing the Fourier components, and to process outputs from the one or more quantum circuits to generate results of the one or more arithmetic functions, wherein the results are used to generate the corresponding output data.

Abstract: There is provided a series of steps, according to user-defined instructions, that enhance a quantum state preparation circuit encoding some multivariate probability distribution such that the circuit further includes dimensions pertaining to sums, products and maxima/minima of other dimensions, and optionally includes a further “flag” qubit that will act as a conditional control in quantum Monte Carlo integration (QMCI). The series of steps are useful for computations in many applications in science and engineering.

Abstract: There is provided a method for modifying any quantum phase-estimation-free quantum amplitude-estimation algorithm, to improve the statistical performance and robustness of the amplitude estimation. A phase-estimation-free amplitude-estimation algorithm provides an estimate for the amplitude of a desired quantum state, realised by performing classical post-processing for combined measurement data resulting from a number of different quantum circuits derived from the desired quantum state. The method for modifying any such algorithm prepares quantum circuits that each correspond to different initial states (chosen either quasi-randomly, randomly, or deterministically). These are prepared using linear combinations of unitary operations, and each initial state corresponds to a state rotated in the two-dimensional invariant subspace to a corresponding initial angle.

Abstract: A quantum computing system includes a classical computer coupled in combination with a quantum computer, wherein the quantum computing system is configurable to execute program instructions to process input data to generate corresponding output data. The program instructions include one or more arithmetic functions to be executed using the quantum computer. The quantum computing system is configured to apply a transformation to transform the one or more arithmetic functions into a series of Fourier components that are executable using the quantum computer by using one or more quantum circuits utilizing rotation gates acting on qubits representing the Fourier components, and to process outputs from the one or more quantum circuits to generate results of the one or more arithmetic functions, wherein the results are used to generate the corresponding output data.

Abstract: A method of operating a quantum information processing system. The quantum information processing system includes an array of connected qubits. The method of operating the quantum information processing system uses a linear network coding solution to performing an operation between the quantum states of two or more qubits of the array.

Abstract: A method of maintaining data packet forwarding information in a first network node of a wireless mesh communications network having a plurality of network nodes interconnected by wireless communications links is disclosed. The method includes receiving respective activity indicators for neighbour network nodes connected with the first network node by respective wireless communications links, and determining respective link indicators for the outgoing wireless communications links of the first network node, each such link indicator being indicative of a data packet transmission characteristic for the link concerned.

Abstract: A method of maintaining data packet forwarding information in a first network node of a wireless mesh communications network having a plurality of network nodes interconnected by wireless communications links is disclosed. The method includes receiving respective activity indicators for neighbour network nodes connected with the first network node by respective wireless communications links, and determining respective link indicators for the outgoing wireless communications links of the first network node, each such link indicator being indicative of a data packet transmission characteristic for the link concerned.