Terra Quantum AG

A system and method for authenticating an optical fiber key includes selecting a plurality of at least partially randomized challenge pulse parameters, generating a first optical challenge pulse based on the plurality of at least partially randomized challenge pulse parameters, determining an optical response signal based on a reflected signal of the first optical challenge pulse from the optical fiber key, applying a comparing algorithm the optical response signal and an expected response based on previously recorded optical response signals of the optical fiber key to a reference optical challenge pulse for determining a similarity metric, and authenticating the optical fiber key based on the similarity metric.

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.

A high-temperature superconducting qubit implements a quantum mechanical two-level system. The high-temperature superconducting qubit comprises a first superconductor, a second superconductor, and an overlap region. The first superconductor comprises a first high-temperature superconductor material. The second superconductor comprises a second high-temperature superconductor material. In the overlap region, at least a first section of the first surface and at least a second section of the second surface overlap, the first section and the second section are arranged in parallel at a distance corresponding to a predefined distance, and the first orientation and the second orientation are arranged with an angle corresponding to a predefined angle. The high-temperature superconducting qubit comprises a Josephson junction between the first high-temperature superconductor material and the second high-temperature superconductor material. The Josephson junction provides the quantum mechanical two-level system of the high-temperature superconducting qubit.

A ferroelectric nanoparticle capacitor-device comprises a pair of conductive elements electrically insulated from each other, and ferroelectric nanoparticles arranged between the conductive elements of the pair. The ferroelectric nanoparticles are adapted to provide at least three polarization states with different total ferroelectric polarizations.

A system for quantum key distribution includes a first data processing device; a second data processing device; and a transmission line extending between the first data processing device and the second data processing device. The transmission line comprises an inner optical fiber, a shielding layer surrounding the inner optical fiber, and an outer optical fiber surrounding the shielding layer. The first data processing device and the second data processing device are configured to determine a shared key by quantum key distribution via quantum signals along the inner optical fiber. The system is configured to determine outer signal losses along the outer optical fiber.

A computer-implemented method for providing content of a content author for authentication includes obtaining, by the content author, a first author fragment of content; generating a first state author vector from the first author fragment of content; and creating a first block of key information based on the first author fragment of content, wherein the first block of key information comprises information of the first state author vector and a first digital signature.

A method and system for encrypted messaging includes first and second client devices and a quantum key device having a quantum random number generator. The generator provides a first quantum random signal, and the key device provides a symmetric first master key from the first quantum random signal. The master key is transmitted to the first client device and stored. The key device uses the master key to generate an encrypted package by encrypting one of a plurality of keys. The key device generates a second encrypted package. The first pairing key is provided to the first client device by decrypting the first encrypted package using the first master key and providing the first pairing key in the second client device by decrypting the second encrypted package using the second master key to establish an encrypted connection between the first and second client devices.

A method for labeling an input vector of features with an output label using a variational quantum circuit given a labeling task includes separating the input vector of features into a plurality of sub-vectors of input data, initializing a plurality of computation qubits in an initial state, and subjecting the plurality of computation qubits to a plurality of layers of quantum gates, wherein each layer of the plurality of layers of quantum gates comprises an entangling gate a plurality of encoding gates for encoding the features of one of the sub-vectors into the computation qubits, and a plurality of variational gates, wherein the sub-vectors of input data for two different layers of quantum gates are different, and wherein variational parameters associated with the variational gates are optimized for predicting an optimal output label for the input vector of features in view of the labeling task according to a training algorithm.

A method for driving a quantum computational network for determining an extremal value of a cost function for solutions of a quadratic unconstrained binary optimization problem includes initializing qubits, sequentially applying layers of quantum gates to the qubits, determining an output state of the quantum computational network for obtaining a solution associated with the set of variational parameters {right arrow over (θ)}, and determining an output state for shifted variational parameters {right arrow over (θ)}* to evaluate a partial derivative with respect to the subset of the variational parameters {right arrow over (θ)} for determining a gradient of the cost function based on the output state for the shifted variational parameters {right arrow over (θ)}*, and by updating the variational parameters {right arrow over (θ)} based on an update function of a moving average over the gradient of the cost function and of a moving average over the squared gradient of the cost function.

A computer-implemented method for simulating fluid flow includes solving a Lattice Boltzmann equation for a distribution function, wherein the distribution function is represented in a tensor-train format, and/or all operations carried out for computing the distribution function are carried out with the distribution function in the tensor-train format, the distribution function and/or the tensor train format comprising at least one tensor train, the tensor train having at least one tensor train core.