1123 results about "Quantum computer" patented technology

A portable encryption device with logon access controlled by an encryption key, with an on board cryptographic processor for reconstituting the encryption key from a plurality of secrets generated by a secret sharing algorithm, optionally shrouded with external secrets using an invertible transform resistant to quantum computing attacks. Another embodiment provides file decryption controlled by a file encryption key, with the on board cryptographic processor reconstituting the file encryption key from a version of the file encryption key which has been shrouded with a network authorization code. A method for encryption of a plaintext file by hashing, compressing, and encrypting the plaintext file, hashing the ciphertext, hashing the plaintext hash and the ciphertext hash, and sealing the ciphertext together with the resulting hash. A portable encryption device for performing the method is also disclosed.

A long range, periodically ordered array of discrete nano-features (10), such as nano-islands, nano-particles, nano-wires, non-tubes, nano-pores, nano-composition-variations, and nano-device-components, are fabricated by propagation of a self-assembling array or nucleation and growth of periodically aligned nano-features. The propagation may be induced by a laterally or circularly moving heat source, a stationary heat source arranged at an edge of the material to be patterned (12), or a series of sequentially activated heaters or electrodes. Advantageously, the long-range periodic array of nano-features (10) may be utilized as a nano-mask or nano-implant master pattern for nano-fabrication of other nano-structures. In addition, the inventive long-range, periodically ordered arrays of nano-features are useful in a variety of nanoscale applications such as addressable memories or logic devices, ultra-high-density magnetic recording media, magnetic sensors, photonic devices, quantum computing devices, quantum luminescent devices, and efficient catalytic devices.

A quantum computing structure comprising a superconducting phase-charge qubit, wherein the superconducting phase-charge qubit comprises a superconducting loop with at least one Josephson junction. The quantum computing structure also comprises a first mechanism for controlling a charge of the superconducting phase-charge qubit and a second mechanism for detecting a charge of the superconducting phase-charge qubit, wherein the first mechanism and the second mechanism are each capacitively connected to the superconducting phase-charge qubit.

The invention provides a wireless local area network security communication method based on quantum key distribution. The method comprises the following steps that: (1) identity authentication based on quantum keys is carried out; (2) quantum key negotiation is carried out; and (3) encryption is started. With the method of the invention adopted, information exchange between a faked access point and an applicant, the waste of system resources or a caused denial of service attack can be can avoided; bidirectional authentication between the applicant and an authentication server as well as between the applicant and an authenticator can be realized, and therefore, the security of the identity authentication is greatly improved; keys produced in the identity authentication can be adopted to protect message authentication in key negotiation, and therefore, attacks such as the tamper of a intermediary can be prevented; the security of key negotiation based on quantum technology is guaranteed by physical laws, and therefore, the key negotiation based on quantum technology has undecodability, and can withstand the decoding of a quantum computer with strong computational ability, and therefore, the security of a whole system can be enhanced.

A method of simulating a molecular system using a hybrid computer is provided. The hybrid computer comprises a classical computer and a quantum computer. The method uses atomic coordinates {right arrow over (R)}_n and atomic charges Z_n of a molecular system to compute a ground state energy of the molecular system using the quantum computer. The ground state energy is returned to the classical computer and the atomic coordinates are geometrically optimized on the classical computer based on information about the returned ground state energy of the atomic coordinates in order to produce a new set of atomic coordinates {right arrow over (R)}′_n for the molecular system. These steps are optionally repeated in accordance with a refinement algorithm until a predetermined termination condition is achieved

A method of simulating a molecular system using a hybrid computer is provided. The hybrid computer comprises a classical computer and a quantum computer. The method uses atomic coordinates {right arrow over (R)}_n and atomic charges Z_n of a molecular system to compute a ground state energy of the molecular system using the quantum computer. The ground state energy is returned to the classical computer and the atomic coordinates are geometrically optimized on the classical computer based on information about the returned ground state energy of the atomic coordinates in order to produce a new set of atomic coordinates {right arrow over (R)}′_n for the molecular system. These steps are optionally repeated in accordance with a refinement algorithm until a predetermined termination condition is achieved

A problem solving system includes a number of special-purpose computers including at least one quantum computer. Problems are decomposed into sub-problems and routed to one of the special-purpose computers based on the problem class to which the problem belongs. Sub-solutions produced by the special-purpose computers are complied to produce at least an approximate solution to the problem.

A method and structure for a d-wave qubit structure includes a qubit disk formed at a multi-crystal junction (or qubit ring) and a superconducting screening structure surrounding the qubit. The structure may also include a superconducting sensing loop, where the superconducting sensing loop comprises an s-wave superconducting ring. The structure may also include a superconducting field effect transistor.

A quantum computing device magnetic memory is described. The quantum computing device magnetic memory is coupled with a quantum processor including at least one quantum device corresponding to at least one qubit. The quantum computing device magnetic memory includes magnetic storage cells coupled with the quantum device(s) and bit lines coupled to the magnetic storage cells. Each of the magnetic storage cells includes at least one magnetic junction. The magnetic junction(s) include a reference layer, a nonmagnetic spacer layer, and a free layer. The nonmagnetic spacer layer is between the reference layer and the free layer. The magnetic junction(s) are configured to allow the free layer to be switched between stable magnetic states. The magnetic junction(s) are configured such that the free layer has a nonzero initial writing spin transfer torque in an absence of thermal fluctuations.

A quantum processor is operable as a universal adiabatic quantum computing system. The quantum processor includes physical qubits, with at least a first and second communicative coupling available between pairs of qubits via an in-situ tunable superconducting capacitive coupler and an in-situ tunable superconducting inductive coupler, respectively. Tunable couplers provide diagonal and off-diagonal coupling. Compound Josephson junctions (CJJs) of the tunable couplers are responsive to a flux bias to tune a sign and magnitude of a sum of a capacitance of a fixed capacitor and a tunable capacitance which is mediated across a pair of coupling capacitors. The qubits may be hybrid qubits, operable in a flux regime or a charge regime. Qubits may include a pair of CJJs that interrupt a loop of material and which are separated by an island of superconducting material which is voltage biased with respect to a qubit body.

In an operation of two qubit gate having failure information related to success or failure, by using a code to concatenate N-error-correcting code transversally executing a Pauli gate, a Hadamard gate and a CNOT gate, an error-correction is executed by an error-correcting teleportation, and the CNOT gate is executed to an encoded qubit by the error-correcting teleportation. In Bell measurement of the error-correcting teleportation, when a measurement result of non-encoded qubit is processed, by suitably defining failure information of the encoded qubit of level (l+1) from the failure information of encoded qubits of level l, the measurement result of the encoded qubit of each level is determined, and the failure information of the encoded qubit of each level is defined. As a result, a measurement result of a logical qubit as the encoded qubit of the highest level is determined.

A universal quantum computer may be emulated by a classical computing system that uses an electronic signal of bounded duration and amplitude to represent an arbitrary initial quantum state. The initial quantum state may be specified by inputs provided to the system and may be encoded in the signal, which is derived from a collection of phase-coherent coherent basis signals. Unitary quantum computing gate operations, including logical operations on qubits or operations that change the phase of a qubit, may be performed using analog electronic circuits within the quantum computing emulation device. These circuits, which may apply a matrix transformation to the signals representing the initial quantum state, may include four-quadrant multipliers, operational amplifiers, and analog filters. A measurement component within the quantum computing emulation device may produce a digital signal output representing the transformed quantum state. The gate operation(s) performed may be selected from among multiple supported operations.

An (N+1) number of physical systems each having five energy levels |0>, |1>, |2>, |3>, and |4>, a qubit being expressed by |0> and |1>, are provided in an optical cavity having a cavity mode resonant with |2>-|3>, such that an N number of control systems and a target system are prepared. The target system is irradiated with light pulses resonant with |0>-|4>, |1>-|4>, and |2>-|4> to change a superposed state |c> to |2>. All of the physical systems are irradiated with light pulses resonant with |0>-|3> and |1>-|3>, and a phase of the light pulse resonant with the target system is shifted by a specific value dependent on a unitary transformation U. The target system is irradiated with light pulses resonant with |0>-|4>, |1>-|4>, and |2>-|4>, with a phase difference between them being set to a specific value dependent on the unitary transformation U, to return |2> to |c>.

Computational systems implement problem solving using heuristic solvers or optimizers. Such may iteratively evaluate a result of processing, and modify the problem or representation thereof before repeating processing on the modified problem, until a termination condition is reached. Heuristic solvers or optimizers may execute on one or more digital processors and/or one or more quantum processors. The system may autonomously select between types of hardware devices and/or types of heuristic optimization algorithms. Such may coordinate or at least partially overlap post-processing operations with processing operations, for instance performing post-processing on an ith batch of samples while generating an (i+1)th batch of samples, e.g., so post-processing operation on the ith batch of samples does not extend in time beyond the generation of the (i+1)th batch of samples. Heuristic optimizers selection is based on pre-processing assessment of the problem, e.g., based on features extracted from the problem and for instance, on predicted success.

A method to electronically modulate the energy gap and band-structure of semiconducting carbon nanotubes is proposed. Results show that the energy gap of a semiconducting nanotube can be narrowed when the nanotube is placed in an electric field perpendicular to the tube axis. Such effect in turn causes changes in electrical conductivity and radiation absorption characteristics that can be used in applications such as switches, transistors, photodetectors and polaron generation. By applying electric fields across the nanotube at a number of locations, a corresponding number of quantum wells are formed adjacent to one another. Such configuration is useful for Bragg reflectors, lasers and quantum computing.

A nondeterministic quantum CNOT gate (10) for photon qubits, with success probability 1/9, uses beamsplitters (B1–B5) with selected reflectivities to mix control and target input modes. It may be combined with an atomic quantum memory to construct a deterministic CNOT gate, with applications in quantum computing and as a Bell-state analyser.