Abstract: A photonic interconnect method avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The method can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors, which can be fabricated at defects in a photonic bandgap crystal, can be employed for the photonic interconnect method. The interconnect method can be used for both classical and quantum information processing.

Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.

Abstract: Structures and methods allow: transfer of quantum information represented using the states of light to a representation using the states of matter systems; transfer of quantum information represented by the states of matter systems to a representation using the states of light; and error resistant encoding of quantum information using entangled states of matter and light to minimize errors.

Abstract: Various embodiments of the present invention are directed optical-based quantum random number generators. In one embodiment, a quantum random number generator includes an input state generator that generates a first optical quantum system and a second optical quantum system in an entangled state, a detector that measures the state of the first optical quantum system and the state of the second optical quantum system, and a system control that evaluates a result obtained from measuring the state of the first optical quantum system and state of the second optical quantum system to determine whether or not to append a number associated with the result to the sequence of random numbers. The quantum random number generator also include state controllers, located between the input state generator and the detector, that are operationally controlled by the system control to maintain the entangled state, based on results obtained from previous measurements performed on the first and second optical quantum systems.

Abstract: Various embodiments of the present invention are directed to methods for generating an entangled state of qubits. In one embodiment of the present invention, a method for preparing an entangled state of qubits comprises providing a probe and N non-interacting qubits, each qubit comprises a linear superposition of two basis states. The probe is transmitted into an interaction region that separately couples the probe to each of the qubits and produces a number of different probes. A linear superposition of states is output from the interaction region, each state in the linear superposition of states comprises a tensor product of entangled basis states and one of the different probes. The linear superposition of states is projected into one of the entangled states by measuring the state of the probe.

Abstract: Nonlinear elements can efficiently implement quantum information processing systems such as controlled phase shifters, non-absorbing detectors including parity detectors, quantum subspace projections, non-absorbing Bell state analyzers, non-absorbing encoders/entanglers, and fundamental quantum gates such as CNOT gates. The non-absorbing detectors permit improvements in the efficiency of a probabilistic quantum gate by permitting reuse of the same photonic resources during multiple passes through the probabilistic gate.

Abstract: A photonic interconnect system avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The system can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors for the photonic interconnect system can be efficiently fabricated at defects in a photonic bandgap crystal. The interconnect system can be used for both classical and quantum information processing.

Abstract: Various embodiments of the present invention are directed to methods and systems for circumventing, and altering transmission-channel users of, transmission-channel disruptions. In one embodiment of the present invention, a source encodes information in a first signal and transmits the first signal in a source channel to a multiplexer. The multiplexer distributes the first signal over N transmission channels. A demultiplexer combines the signals distributed over the N transmission channels into a second signal encoding of the information. The distribution system also includes a detector that receives the second signal output from the demultiplexer, and one or more detectors that receive one or more additional signals output from the demultiplexer. The additional signals are produced by the demultiplexer when a disruption occurs in one or more of the transmission channels and are used to alert transmission-channel users of the disruption.

Abstract: Quantum information processing structures and methods use photons and four-level matter systems in electromagnetically induced transparency (EIT) arrangements for one and two-qubit quantum gates, two-photon phase shifters, and Bell state measurement devices. For efficient coupling of the matter systems to the photons while decoupling the matter systems from the phonon bath, molecular cages or molecular tethers maintain the atoms within the electromagnetic field of the photon, e.g., in the evanescent field surrounding the core of an optical fiber carrying the photons. To reduce decoherence caused by spontaneous emissions, the matter systems can be embedded in photonic bandgap crystals or the matter systems can be selected to include metastable energy levels.

Abstract: The states of matter system (110) having only ones basis state that couples to an excited state can be entangled using measurements of photons during transitions from the excited state. High efficiency of entanglement operation can be achieved by repeating the measurements after performing bit flips on the matter systems (110). High efficiency of entanglement operation can be achieved using non-absorbing parity measurements on the emitted photons so that measured photons can be subsequently manipulated and measured to near-deterministically produce entangled states. Such entanglement operations can be employed to construct cluster states suitable for simulating arbitrary logic networks.

Abstract: A photonic interconnect system avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The system can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors for the photonic interconnect system can be efficiently fabricated at defects in a photonic bandgap crystal. The interconnect system can be used for both classical and quantum information processing.

Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.

Abstract: A security system uses a source capable of producing an entangled state of a sensing mode and a reference mode. The sensing mode has a path that enters an area around an object being secured. A state measurement system in the security system can measure a combination of the sensing mode after traversal of the sensing path and the reference mode after traversal of a reference path.

Abstract: Nonlinear elements can efficiently implement quantum information processing systems such as controlled phase shifters, non-absorbing detectors including parity detectors, quantum subspace projections, non-absorbing Bell state analyzers, non-absorbing encoders/entanglers, and fundamental quantum gates such as CNOT gates. The non-absorbing detectors permit improvements in the efficiency of a probabilistic quantum gate by permitting reuse of the same photonic resources during multiple passes through the probabilistic gate.

Abstract: Systems and methods convert or transfer quantum information from one photonic representation or state to another. This permits conversion of quantum information from one encoding to another and to representations that are convenient, efficient, or required for desired manipulations.

Abstract: A quantum random number generator uses measurements of a quantum state to generate a random value and to authenticate that the quantum state had the required properties for generation of a random series having the desired statistics. One exemplary embodiment generates an entangled photon pair in the singlet Bell state, measures one photon to extract a random value, and measures the other photon for confirmation that the photon pair were in the singlet Bell state. Another embodiment of the invention performs tomographic analysis of a state used for random number generation to confirm that the state used had the desired properties.

Abstract: Various embodiments of the present invention are directed to methods for determining a phase shift acquired by an entangled N-qubit system represented by a NOON state. In one embodiment, a probe electromagnetic field is coupled with each qubit system. The phase shift acquired by the qubit systems is transferred to the probe electromagnetic field by transforming each qubit-system state into a linear superposition of qubit basis states. An intensity measurement is performed on the probe electromagnetic field in order to obtain a corresponding measurement result. A counter associated with a measurement-result interval is incremented, based on the measurement result falling within the measurement-result interval. A frequency distribution is produced by normalizing the counter associated with each measurement-result interval for a number of trials.

Abstract: A photonic interconnect system avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The system can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors for the photonic interconnect system can be efficiently fabricated at defects in a photonic bandgap crystal. The interconnect system can be used for both classical and quantum information processing.

Abstract: Quantum testing can compare unknown photon states in a manner suitable for a validation check of a quantum digital signature, testing of the operation of a quantum gate, or detecting of entanglement. The effect of the QSC system can be used to entangle input photon states. QSC system can include a control swap gate having a control channel that is measured, a beam splitter and a controlled phases gate with a control channel that is measured, or a beam splitter with a parity detector on an output channel. The operation of the QSC system can also be used to generate an entangled photon state.

Abstract: A photonic interconnect system avoids high capacitance electric interconnects by using optical signals to communicate data between devices. The system can provide massively parallel information output by mapping logical addresses to frequency bands, so that modulation of a selected frequency band can encode information for a specific location corresponding to the logical address. Wavelength-specific directional couplers, modulators, and detectors for the photonic interconnect system can be efficiently fabricated at defects in a photonic bandgap crystal.