Abstract: A computer-implemented postselection-free method of initializing qubits in a quantum computer, comprising: preparing at least one data qubit and a plurality of auxiliary qubits in respective initial states, wherein each of the at least one data qubit and the plurality of auxiliary qubits has a respective probability of being prepared with an error; and, performing a plurality of non-measurement multi-qubit quantum logic operations that propagate errors between the at least one data qubit and the plurality of auxiliary qubits so as to reduce the probability of an error affecting the at least one data qubit.

Abstract: An optomechanical gravimeter includes: a first and second accelerometer; and a spacer member interposed between the first accelerometer and the second accelerometer such that the first accelerometer and the second accelerometer independently include: a basal member; a test mass disposed on the basal member; a flexural member interposed between the basal member and the test mass such that the test mass is moveably disposed on the basal member via flexing of the flexural member; an armature disposed on the basal member and opposing the test mass and the flexural member such that: the armature is spaced apart from the test mass; a cavity including: a first mirror disposed on the test mass; a second mirror disposed on the armature, the spacer member providing a substantially constant distance of separation between a first measurement point of the first accelerometer and a second measurement point of the second accelerometer.

Abstract: An optomechanical laser includes: a basal member; a mechanical transducer; a laser disposed on the mechanical transducer, the laser being displaced along the displacement axis in response to a displacement of the mechanical transducer relative to the basal member; a mirror disposed on the armature in optical communication with the laser and opposing the laser; the armature disposed on the basal member and rigidly connecting the mirror to the basal member such that the mirror and the armature move in synchrony with the basal member, and the armature provides a substantially constant distance between the basal member and the mirror; and a cavity comprising: the laser; the mirror; and a cavity length between the laser and the mirror that changes in response to displacement of the laser according to the displacement of the mechanical transducer relative to the basal member, the optomechanical laser providing laser light.

Abstract: An optomechanical laser includes: a basal member; a mechanical transducer; a laser disposed on the mechanical transducer, the laser being displaced along the displacement axis in response to a displacement of the mechanical transducer relative to the basal member; a mirror disposed on the armature in optical communication with the laser and opposing the laser; the armature disposed on the basal member and rigidly connecting the mirror to the basal member such that the mirror and the armature move in synchrony with the basal member, and the armature provides a substantially constant distance between the basal member and the mirror; and a cavity comprising: the laser; the mirror; and a cavity length between the laser and the mirror that changes in response to displacement of the laser according to the displacement of the mechanical transducer relative to the basal member, the optomechanical laser providing laser light.

Abstract: An optomechanical gravimeter includes: a first and second accelerometer; and a spacer member interposed between the first accelerometer and the second accelerometer such that the first accelerometer and the second accelerometer independently include: a basal member; a test mass disposed on the basal member; a flexural member interposed between the basal member and the test mass such that the test mass is moveably disposed on the basal member via flexing of the flexural member; an armature disposed on the basal member and opposing the test mass and the flexural member such that: the armature is spaced apart from the test mass; a cavity including: a first mirror disposed on the test mass; a second mirror disposed on the armature, the spacer member providing a substantially constant distance of separation between a first measurement point of the first accelerometer and a second measurement point of the second accelerometer.

Abstract: A thermometer includes a substrate; an optical resonator disposed on the substrate and including an optical resonance, the optical resonator being configured to receive a resonant frequency corresponding to the optical resonance; and a waveguide disposed on the substrate proximate to the optical resonator to receive input light, to communicate the resonant frequency to the optical resonator, and to transmit output light; wherein an aperture is interposed between: the substrate and the optical resonator, the substrate and the waveguide, or a combination comprising at least one of the foregoing, and the thermometer is configured to change the optical resonance in response to a change in temperature of the optical resonator.

Abstract: An optical detector for detecting radio frequency (RF) signals, the optical detector comprising a light source and a photodetector, and an electrical circuit comprising a position dependent capacitor and a bias voltage source adapted for providing a bias voltage for biasing the position dependent capacitor, the position dependent capacitor comprising an electrode and a membrane being displaceable in reaction to RF signals incident on the membrane, the membrane being metallized, has a thickness of less than 1 ?m and a quality factor, Qm, of at least 20,000, and the distance between the membrane and the electrode being less than 10 ?m.

Abstract: An optical detector for detecting radio frequency (RF) signals, the optical detector comprising a light source and a photodetector, and an electrical circuit comprising a position dependent capacitor and a bias voltage source adapted for providing a bias voltage for biasing the position dependent capacitor, the position dependent capacitor comprising an electrode and a membrane being displaceable in reaction to RF signals incident on the membrane, the membrane being metallized, has a thickness of less than 1 ?m and a quality factor, Qm, of at least 20,000, and the distance between the membrane and the electrode being less than 10 ?m.

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 thermometer includes a substrate; an optical resonator disposed on the substrate and including an optical resonance, the optical resonator being configured to receive a resonant frequency corresponding to the optical resonance; and a waveguide disposed on the substrate proximate to the optical resonator to receive input light, to communicate the resonant frequency to the optical resonator, and to transmit output light; wherein an aperture is interposed between: the substrate and the optical resonator, the substrate and the waveguide, or a combination comprising at least one of the foregoing, and the thermometer is configured to change the optical resonance in response to a change in temperature of the optical resonator.

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 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.