Abstract: A quantum computing system, method, and computer readable medium involves initializing a state of a resonator-coupled quantum emitter having at least four levels arranged in an N-configuration, the N-configuration having a first ground state, a second ground state, a first excited state and a second excited state. A frequency of a first transition between the first ground state and the first excited state is tuned, a frequency of a second transition between the second ground state and the second excited state is tuned, and a frequency of a third transition between the second ground state and the first excited state is tuned. A plurality of photons are fed at a frequency corresponding to the frequency of the second transition, thereby entangling the plurality of photons to the resonator-coupled quantum emitter.

Abstract: A quantum computing system, method and computer readable medium involve a vacuum enclosure for sustaining a vacuum below 10?3 millibar, optical resonators tuned to a resonance of an alkali atom, and a trapping laser for maintaining the alkali atom within a mode of the optical resonators. An atom excitation laser induces photon emissions, a plurality of waveguides couple photons to and from the optical resonators, and a plurality of detectors detect a presence or absence of an atom-resonator coupling. A processor receives output signals from the detectors and controls optical switches for switching between two or more of the plurality of waveguides.

Abstract: Systems and methods for a quantum computing include a plurality of photonic processing stages, a plurality of heralding-free connections, and circuitry configured to regulate photon flow between adjacent stages such that decisions about stage settings or flow between adjacent stages are free of input from a previous stage. Each heralding-free connection is located between adjacent photonic processing stages. Each photonic processing stage includes at least two of an optical switch, a beam splitter, a waveguide or a photon generator. Methods include transmitting or receiving a plurality of photons via a plurality of heralding-free connections, and regulating photon flow between adjacent stages such that decisions about stage settings or flow between adjacent stages are free of input from a previous stage.

Abstract: Systems and methods for generating photonic graph states for quantum computing include coupling a quantum emitter to a cavity, generating a first dirty photon having a first temporal profile, using the first dirty photon to form a first photonic qubit, generating a second dirty photon having a second temporal profile, using the second dirty photon to form a second photonic qubit, using the quantum emitter coupled to the cavity to entangle the first photonic qubit with the second photonic qubit to form a pair of entangled photonic qubits, and using the pair of entangled photonic qubits for quantum computation.

Abstract: A quantum computing system, method and computer readable medium involve a vacuum chamber, an atom source input associated with the vacuum chamber, a Photonic Integrated Circuit (PIC) having an interaction region configured to interact with an atom from the atom source, a coupling location for atom positioning, a trapping laser for trapping the atom in the coupling location, an excitation laser for manipulating an electronic state or a nuclear state of the atom, a waveguide for guiding input light to the coupling location, and an output channel for directing quantum light generated at the coupling location, out of the vacuum chamber as a resource for quantum computing. The coupling location is associated with the PIC, and the interaction region of the PIC is arranged for at least partial exposure to the vacuum.

Abstract: Systems and methods for a quantum computing include a plurality of photonic processing stages, a plurality of heralding-free connections, and circuitry configured to regulate photon flow between adjacent stages such that decisions about stage settings or flow between adjacent stages are free of input from a previous stage. Each heralding-free connection is located between adjacent photonic processing stages. Each photonic processing stage includes at least two of an optical switch, a beam splitter, a waveguide or a photon generator. Methods include transmitting or receiving a plurality of photons via a plurality of heralding-free connections, and regulating photon flow between adjacent stages such that decisions about stage settings or flow between adjacent stages are free of input from a previous stage.

Abstract: Systems and methods for generating photonic graph states for quantum computing include coupling a quantum emitter to a cavity, generating a first dirty photon having a first temporal profile, using the first dirty photon to form a first photonic qubit, generating a second dirty photon having a second temporal profile, using the second dirty photon to form a second photonic qubit, using the quantum emitter coupled to the cavity to entangle the first photonic qubit with the second photonic qubit to form a pair of entangled photonic qubits, and using the pair of entangled photonic qubits for quantum computation.

Abstract: A quantum computing system, method and computer readable medium involve a vacuum chamber, an atom source input associated with the vacuum chamber, a Photonic Integrated Circuit (PIC) having an interaction region configured to interact with an atom from the atom source, a coupling location for atom positioning, a trapping laser for trapping the atom in the coupling location, an excitation laser for manipulating an electronic state or a nuclear state of the atom, a waveguide for guiding input light to the coupling location, and an output channel for directing quantum light generated at the coupling location, out of the vacuum chamber as a resource for quantum computing. The coupling location is associated with the PIC, and the interaction region of the PIC is arranged for at least partial exposure to the vacuum.

Abstract: A quantum computing system, method, and computer readable medium involves initializing a state of a resonator-coupled quantum emitter having at least four levels arranged in an N-configuration, the N-configuration having a first ground state, a second ground state, a first excited state and a second excited state. A frequency of a first transition between the first ground state and the first excited state is tuned, a frequency of a second transition between the second ground state and the second excited state is tuned, and a frequency of a third transition between the second ground state and the first excited state is tuned. A plurality of photons are fed at a frequency corresponding to the frequency of the second transition, thereby entangling the plurality of photons to the resonator-coupled quantum emitter.

Abstract: A quantum computing system, method and computer readable medium involve a vacuum enclosure for sustaining a vacuum below 10?3 millibar, optical resonators tuned to a resonance of an alkali atom, and a trapping laser for maintaining the alkali atom within a mode of the optical resonators. An atom excitation laser induces photon emissions, a plurality of waveguides couple photons to and from the optical resonators, and a plurality of detectors detect a presence or absence of an atom-resonator coupling. A processor receives output signals from the detectors and controls optical switches for switching between two or more of the plurality of waveguides.

Abstract: A quantum computing method includes initializing a state of a resonator-coupled quantum emitter, receiving at least two photonic graph states, selecting at least one photon from each graph state, feeding the selected photons through an entangling gate via the resonator-coupled quantum emitter, and disentangling the resonator-coupled quantum emitter from the selected photons. Each of the at least two photonic graph states contains at least two photons. The disentangling includes at least one of detecting the state of the resonator-coupled quantum emitter or mapping the state of the resonator-coupled quantum emitter to a state of an additional photon.

Abstract: A quantum computing system includes a first resonator couplable to a first alkali atom, a second resonator couplable to a second alkali atom, and lasers for trapping, cooling, and manipulating the first alkali atom and the second alkali atom. Detectors detect a presence of the trapped first alkali atom and the trapped second alkali atom, and a processor is configured to receive at least one input signal from at least one of the detectors, the input signal indicating a presence of the trapped first alkali atom and the trapped second alkali atom, and, based on the received input, control at least some of the lasers to manipulate at least one of the trapped first alkali atom and the trapped second alkali atom to thereby generate photonic qubits using the trapped first alkali atom or generate entanglement between photonic qubits transmitted to the trapped second alkali atom.

Abstract: A quantum computing system, method and computer readable storage medium involve tuning a whispering-gallery mode optical resonator to support a resonance frequency associated with a transition frequency of an atom. Operation of a laser is controlled to cause the atom to be trapped adjacent the optical resonator and within the evanescent field portion. Based on an atom presence signal from an optical atom presence detector, an indication is provided that the atom is trapped adjacent the optical resonator. A frequency of a cooling laser is controlled to cool the atom, and the optical resonator is configured to define a closed loop-like mode including an evanescent field portion. The trapping laser is configured to cause the atom to be trapped adjacent the whispering-gallery mode resonator, and the cooling laser is configured to manipulate a state of the atom to thereby cool the atom.

Abstract: A quantum computing system comprises a plurality of photonic cavities, a plurality of coupling locations for quantum emitter positioning, a photon generator configured to supply photons to the plurality of photonic cavities, and a plurality of photon output channels downstream of the plurality of cavities to output a graph state. Each coupling location is associated with a differing one of the plurality of photonic cavities. Quantum emitters associated with each coupling location are configured to mediate interactions between consecutive incoming photonic qubits to generate the graph state, and the photonic cavities are configured to couple photonic qubits to the quantum emitters.

Abstract: Generating photonic graph states includes positioning a plurality of quantum emitters at a plurality of coupling sites associated with a plurality of cavities and initializing a state of a quantum emitter qubit associated with each of the plurality of quantum emitters. Photonic qubits are transmitted toward the plurality of the quantum emitters a first instance transmission for generating an entangling gate between the photonic qubits and the quantum emitter qubit in order to entangle the quantum emitter qubit and the photonic qubits. Following the first instance transmission, photonic qubits are transmitted toward the plurality of quantum emitters in a one second instance transmission for generating a SWAP gate between the photonic qubits and the quantum emitter qubits to map the quantum emitter qubits to photonic qubits.

Abstract: A quantum computing system includes a first resonator couplable to a first alkali atom, a second resonator couplable to a second alkali atom, and lasers for trapping, cooling, and manipulating the first alkali atom and the second alkali atom. Detectors detect a presence of the trapped first alkali atom and the trapped second alkali atom, and a processor is configured to receive at least one input signal from at least one of the detectors, the input signal indicating a presence of the trapped first alkali atom and the trapped second alkali atom, and, based on the received input, control at least some of the lasers to manipulate at least one of the trapped first alkali atom and the trapped second alkali atom to thereby generate photonic qubits using the trapped first alkali atom or generate entanglement between photonic qubits transmitted to the trapped second alkali atom.

Abstract: A quantum computing system comprises a plurality of photonic cavities, a plurality of coupling locations for quantum emitter positioning, a photon generator configured to supply photons to the plurality of photonic cavities, and a plurality of photon output channels downstream of the plurality of cavities to output a graph state. Each coupling location is associated with a differing one of the plurality of photonic cavities. Quantum emitters associated with each coupling location are configured to mediate interactions between consecutive incoming photonic qubits to generate the graph state, and the photonic cavities are configured to couple photonic qubits to the quantum emitters.

Abstract: A quantum computing system, method and computer readable storage medium involve tuning a whispering-gallery mode optical resonator to support a resonance frequency associated with a transition frequency of an atom. Operation of a laser is controlled to cause the atom to be trapped adjacent the optical resonator and within the evanescent field portion. Based on an atom presence signal from an optical atom presence detector, an indication is provided that the atom is trapped adjacent the optical resonator. A frequency of a cooling laser is controlled to cool the atom, and the optical resonator is configured to define a closed loop-like mode including an evanescent field portion. The trapping laser is configured to cause the atom to be trapped adjacent the whispering-gallery mode resonator, and the cooling laser is configured to manipulate a state of the atom to thereby cool the atom.

Abstract: A quantum computing system includes a first silicon nitride resonator couplable to a first alkali atom, a second silicon resonator couplable to a second alkali atom, and a plurality of lasers for trapping, cooling, and manipulating the first alkali atom and the second alkali atom. Detectors detect a presence of the trapped first alkali atom and the trapped second alkali atom, and a processor is configured to receive at least one input signal from at least one of the detectors, the input signal indicating a presence of the trapped first alkali atom and the trapped second alkali atom, and, based on the received input, control at least some of the plurality of lasers to manipulate at least one of the trapped first alkali atom and the trapped second alkali atom to thereby generate photonic qubits using the trapped first alkali atom or generate entanglement between photonic qubits transmitted to the trapped second alkali atom.

Abstract: A quantum computing system includes a first silicon nitride resonator couplable to a first alkali atom, a second silicon resonator couplable to a second alkali atom, and a plurality of lasers for trapping, cooling, and manipulating the first alkali atom and the second alkali atom. Detectors detect a presence of the trapped first alkali atom and the trapped second alkali atom, and a processor is configured to receive at least one input signal from at least one of the detectors, the input signal indicating a presence of the trapped first alkali atom and the trapped second alkali atom, and, based on the received input, control at least some of the plurality of lasers to manipulate at least one of the trapped first alkali atom and the trapped second alkali atom to thereby generate photonic qubits using the trapped first alkali atom or generate entanglement between photonic qubits transmitted to the trapped second alkali atom.