Abstract: A method of driving a quantum computational network for finding a solution to a computational problem comprising a system of linear binary relations includes initializing computation qubits, applying a set of quantum gates and measuring an outcome state. A solution is determined based on a plurality of solution candidates, wherein a state of the register qubits is associated with a select one of the binary relations and a state of the ancilla qubits is associated with a solution candidate for the select one of the binary relations. The solution is then iteratively improved.

Abstract: A computer-implemented method for solving an optimizing problem given a function, the method comprising obtaining an approximation of the function in the form of an approximated matrix product operator (MPO) representation of the function, selecting an approximation rank based on the approximated MPO representation, determining a rank-based orthogonal approximation of the approximated MPO representation in the form of an orthogonal MPO with isometric sub-tensors of the approximation rank, encoding the orthogonal approximation into a quantum circuit based on encodings of the isometric sub-tensors into quantum gates, and encoding a n arbitrary power of the orthogonal approximation based on applying the quantum circuit multiple times in a concatenated sequence of quantum circuits to an input quantum state.

Abstract: A computer-implemented method for encoding an intended matrix in a quantum circuit, the method comprising obtaining an MPO representation of the intended matrix; determining an approximation rank for the intended matrix based on the MPO representation; determining an initial guess for an orthogonal approximation of the intended matrix in the form of a tensor network with isometric sub-tensors of the approximation rank; starting with the initial guess, iteratively optimizing the orthogonal approximation of the intended matrix based on an optimization algorithm minimizing a cost function subject to an isometry constraint for the isometric sub-tensors, wherein the cost function attributes a cost to the orthogonal approximation of the intended matrix based on a quality of the orthogonal approximation with respect to the intended matrix, and encoding the orthogonal approximation into a quantum circuit based on encodings of the isometric sub-tensors into quantum gates.

Abstract: The invention relates to a method for determining the component of a magnetic field in a predetermined direction. The method comprises preparing a quantum system in a coherent superposition state (S1), letting the quantum system evolve for a delay time period (S2) and performing a readout operation and a projective measurement on the quantum system (S3). The steps (S1, S2, S3) are iteratively repeated in an iteration loop, wherein the delay time period increases linearly by the same time increment after each iteration. The method further comprises determining the component of the magnetic field in the predetermined direction according to the outcome of the projective measurements (S4).

Abstract: The invention relates to a method for determining the component of a magnetic field in a predetermined direction. The method comprises preparing a quantum system in a coherent superposition state (S1), letting the quantum system evolve for a delay time period (S2) and performing a readout operation and a projective measurement on the quantum system (S3). The steps (S1, S2, S3) are iteratively repeated in an iteration loop, wherein the delay time period increases linearly by the same time increment after each iteration. The method further comprises determining the component of the magnetic field in the predetermined direction according to the outcome of the projective measurements (S4).

Abstract: A method of driving a quantum computational network for finding a solution to a computational problem comprising a system of linear binary relations includes initializing computation qubits, applying a set of quantum gates and measuring an outcome state. A solution is determined based on a plurality of solution candidates, wherein a state of the register qubits is associated with a select one of the binary relations and a state of the ancilla qubits is associated with a solution candidate for the select one of the binary relations. The solution is then iteratively improved.

Abstract: The invention relates to a method for determining the component of a magnetic field in a predetermined direction. The method comprises preparing a quantum system in a coherent superposition state (S1), letting the quantum system evolve for a delay time period (S2) and performing a readout operation and a projective measurement on the quantum system (S3). The steps (S1, S2, S3) are iteratively repeated in an iteration loop, wherein the delay time period increases linearly by the same time increment after each iteration. The method further comprises determining the component of the magnetic field in the predetermined direction according to the outcome of the projective measurements (S4).

Abstract: The present disclosure relates to a tunable waveguide filter input/output coupling arrangement comprising a waveguide part, a coupling iris part and a tunable filter part. The waveguide part runs along a longitudinal extension and has a waveguide width extending perpendicular to the longitudinal extension, and is electrically connected to the tunable filter part by means of the coupling iris part which comprises an opening between the waveguide part and the tunable filter part. The opening is positioned at a certain position along the longitudinal extension. The waveguide part comprises a stub part that has a certain stub length along the longitudinal extension, between an electrical short-circuit end plate and an edge of the opening that is closest to the end plate, where the stub part also has a stub width extending perpendicular to the longitudinal extension.

Abstract: The present disclosure relates to a tunable waveguide filter input/output coupling arrangement comprising a waveguide part, a coupling iris part and a tunable filter part. The waveguide part runs along a longitudinal extension and has a waveguide width extending perpendicular to the longitudinal extension, and is electrically connected to the tunable filter part by means of the coupling iris part which comprises an opening between the waveguide part and the tunable filter part. The opening is positioned at a certain position along the longitudinal extension. The waveguide part comprises a stub part that has a certain stub length along the longitudinal extension, between an electrical short-circuit end plate and an edge of the opening that is closest to the end plate, where the stub part also has a stub width extending perpendicular to the longitudinal extension.