Abstract: Efficient quantum voting with information-theoretic security is provided. A tally quantum node generates a first plurality of ballot quantum states encoding a first bit string, each of the first plurality of ballot quantum states comprising a plurality of qubits. Each of the first plurality of ballot quantum states are distributed to exactly one of a plurality of voter quantum nodes via a quantum network. At least one of the plurality of voter quantum nodes: performs a projective measurement of its one of the first plurality of ballot quantum states, and thereby determining a parity of a random pair of bits of the first bit string; reads a vote; computes a first encoded vote based on the parity and vote; broadcasts the first encoded vote and an identifier of the pair of bits to each other of the plurality of voter quantum nodes. The first bit string is provided to decode the first encoded vote.

Abstract: A system for optically modulating a plurality of optical channels includes a power delivery module adapted to convert a coherent light beam into a plurality of optical channels, at least one optical modulator, optically coupled to the power delivery module, the at least one optical modulator adapted to optically modulate each of the plurality of the optical channels, and a vacuum chamber having a trapping plane therein, the vacuum chamber adapted to generate an addressable array of trapped particles at the trapping plane, wherein each of the plurality of optical channels is optically coupled to at least one of the trapped particles of the addressable array.

Abstract: A quantum computer uses interactions between atomic ensembles mediated by an optical cavity mode to perform quantum computations and simulations. Using the cavity mode as a bus enables all-to-all coupling and execution of non-local gates between any pair of qubits. Encoding logical qubits as collective excitations in ensembles of atoms enhances the coupling to the cavity mode and reduces the experimental difficulty of initial trap loading. By using dark-state transfers via the cavity mode to enact gates between pairs of qubits, the gates become insensitive to the number of atoms within each collective excitation, making it possible to prepare an array of qubits through Poissonian loading without feedback.

Abstract: A system comprising a solid state lattice containing an electronic spin coupled to a nuclear spin; an optical excitation configuration which is arranged to generate first optical radiation to excite the electronic spin to emit output optical radiation without decoupling the electronic and nuclear spins; wherein the optical excitation configuration is further arranged to generate second optical radiation of higher power than the first optical radiation to decouple the electronic spin from the nuclear spin thereby increasing coherence time of the nuclear spin; a first pulse source configured to generate radio frequency (RF) excitation pulse sequences to manipulate the nuclear spin and to dynamically decouple the nuclear spin from one or more spin impurities in the solid state lattice so as to further increase the coherence time of the nuclear spin; a second pulse source configured to generate microwave excitation pulse sequences to manipulate the electronic spin causing a change in intensity of the output optic

Abstract: Two-dimensional coupled resonator optical waveguide arrangements and systems, devices, and methods thereof. Networks of coupled resonator optical waveguides are arranged so as to exploit topological properties of these optical networks. Such arrangement affords topological protection against disorders or perturbations in the network that may hinder or block photon flow. As a result of a disorder, photons traversing along edge states of the array are rerouted based on the disorder or perturbation. Photon routing in the network is accordingly protected against disorder or defects.

Abstract: A magnetometer for sensing a magnetic field may include a solid state electronic spin system, and a detector. The solid state electronic spin system may contain one or more electronic spins that are disposed within a solid state lattice, for example NV centers in diamond. The electronic spins may be configured to receive optical excitation radiation and to align with the magnetic field in response thereto. The electronic spins may be further induced to precess about the magnetic field to be sensed, in response to an external control such as an RF field, the frequency of the spin precession being linearly related to the magnetic field by the Zeeman shift of the electronic spin energy levels. The detector may be configured to detect output optical radiation from the electronic spin, so as to determine the Zeeman shift and thus the magnetic field.

Abstract: A system comprising a solid state lattice containing an electronic spin coupled to a nuclear spin; an optical excitation configuration which is arranged to generate first optical radiation to excite the electronic spin to emit output optical radiation without decoupling the electronic and nuclear spins; wherein the optical excitation configuration is further arranged to generate second optical radiation of higher power than the first optical radiation to decouple the electronic spin from the nuclear spin thereby increasing coherence time of the nuclear spin; a first pulse source configured to generate radio frequency (RF) excitation pulse sequences to manipulate the nuclear spin and to dynamically decouple the nuclear spin from one or more spin impurities in the solid state lattice so as to further increase the coherence time of the nuclear spin; a second pulse source configured to generate microwave excitation pulse sequences to manipulate the electronic spin causing a change in intensity of the output optic

Abstract: A novel method and apparatus for long distance quantum communication in realistic, lossy photonic channels is disclosed. The method uses single emitters of light as intermediate nodes in the channel. One electronic spin and one nuclear spin coupled via the contact hyperfine interaction in each emitter, provide quantum memory and enable active error purification. It is shown that the fixed, minimal physical resources associated with these two degrees of freedom suffice to correct arbitrary errors, making our protocol robust to all realistic sources of decoherence. The method is particularly well suited for implementation using recently-developed solid-state nano-photonic devices.

Abstract: A quantum ticket is defined by a unique serial number; and a set of qubits, each qubit encoding quantum information. The serial number and the set of qubits are distributed only among one or more trusted verifiers who require a tolerance fidelity Ftol in order to authenticate the token, where Ftol represents a minimum percentage of correct outcomes during authentication of the serial number and the set of qubits. The experimental fidelity Fexp for the quantum token is greater than the Ft0i set by the verifiers, so that an honest user of the quantum ticket who achieves Fexp is exponentially likely to be successfully authenticated when seeking authentication by any of the trusted verifiers. The forging fidelity Fforg for the quantum token is less than Ft0i, so that a dishonest user who achieves Fforg and attempts forgery of the quantum ticket is exponentially likely to fail to obtain authentication for his forged ticket.

Abstract: Two-dimensional coupled resonator optical waveguide arrangements and systems, devices, and methods thereof. Networks of coupled resonator optical waveguides are arranged so as to exploit topological properties of these optical networks. Such arrangement affords topological protection against disorders or perturbations in the network that may hinder or block photon flow. As a result of a disorder, photons traversing along edge states of the array are rerouted based on the disorder or perturbation. Photon routing in the network is accordingly protected against disorder or defects.

Abstract: A novel method and apparatus for long distance quantum communication in realistic, lossy photonic channels is disclosed. The method uses single emitters of light as intermediate nodes in the channel. One electronic spin and one nuclear spin coupled via the contact hyperfine interaction in each emitter, provide quantum memory and enable active error purification. It is shown that the fixed, minimal physical resources associated with these two degrees of freedom suffice to correct arbitrary errors, making our protocol robust to all realistic sources of decoherence. The method is particularly well suited for implementation using recently-developed solid-state nano-photonic devices.

Abstract: A method is disclosed for increasing the sensitivity of a solid state electronic spin based magnetometer that makes use of individual electronic spins or ensembles of electronic spins in a solid-state lattice, for example NV centers in a diamond lattice. The electronic spins may be configured to undergo a Zeeman shift in energy level when photons of light are applied to the electronic spins followed by pulses of an RF field that is substantially transverse to the magnetic field being detected. The method may include coherently controlling the electronic spins by applying to the electronic spins a sequence of RF pulses that dynamically decouple the electronic spins from mutual spin-spin interactions and from interactions with the lattice. The sequence of RF pulses may be a Hahn spin-echo sequence, a Can Purcell Meiboom Gill sequence, or a MREV8 pulse sequence, by way of example.

Abstract: A magnetometer for sensing a magnetic field may include a solid state electronic spin system, and a detector. The solid state electronic spin system may contain one or more electronic spins that are disposed within a solid state lattice, for example NV centers in diamond. The electronic spins may be configured to receive optical excitation radiation and to align with the magnetic field in response thereto. The electronic spins may be further induced to precess about the magnetic field to be sensed, in response to an external control such as an RF field, the frequency of the spin precession being linearly related to the magnetic field by the Zeeman shift of the electronic spin energy levels. The detector may be configured to detect output optical radiation from the electronic spin, so as to determine the Zeeman shift and thus the magnetic field.