Abstract: This disclosure relates to a magnetometer for measuring a magnetic field. The magnetometer comprises a solid state quantum system with at least two quantum spin states. A control signal generator sets the quantum system into a quantum state that accumulates a phase over time depending on the magnetic field. A detector measures a signal from the quantum system indicative of the accumulated phase at a measurement time after the setting of the quantum state. A processor determines a magnetic field measurement based on the signal measured by the detector. Importantly, the quantum system is mounted on a rotator that is configured to rotate the quantum system about a rotation axis that defines an angle with the direction of the magnetic field and at a rotation rate that modulates the magnetic field over the measurement time.

Abstract: This disclosure relates to determining a spatial configuration of multiple nuclei. An electron dipole generates a spatially varying magnetic field such that each of the multiple nuclei is resonant at a respective resonance frequency defined by the magnetic field at a location of that nucleus. A first signal generator generates a first signal at a first signal frequency such that, as a result of dipole-dipole interaction between the electron dipole and a subset of the multiple nuclei that are resonant at the first signal frequency, a phase of the electron dipole is indicative of a number of nuclei that are resonant at the first signal frequency. A readout module determines the phase of the electron dipole, and determines the spatial configuration of the multiple nuclei based on the phase of the electron dipole. As a result of the high spatial resolution of the sensing the nuclear structure of molecules can be determined with low noise.

Abstract: This disclosure relates to a magnetometer for measuring a magnetic field. The magnetometer comprises a solid state quantum system with at least two quantum spin states. A control signal generator sets the quantum system into a quantum state that accumulates a phase over time depending on the magnetic field. A detector measures a signal from the quantum system indicative of the accumulated phase at a measurement time after the setting of the quantum state. A processor determines a magnetic field measurement based on the signal measured by the detector. Importantly, the quantum system is mounted on a rotator that is configured to rotate the quantum system about a rotation axis that defines an angle with the direction of the magnetic field and at a rotation rate that modulates the magnetic field over the measurement time.

Abstract: This disclosure relates to determining a spatial configuration of multiple nuclei. An electron dipole generates a spatially varying magnetic field such that each of the multiple nuclei is resonant at a respective resonance frequency defined by the magnetic field at a location of that nucleus. A first signal generator generates a first signal at a first signal frequency such that, as a result of dipole-dipole interaction between the electron dipole and a subset of the multiple nuclei that are resonant at the first signal frequency, a phase of the electron dipole is indicative of a number of nuclei that are resonant at the first signal frequency. A readout module determines the phase of the electron dipole, and determines the spatial configuration of the multiple nuclei based on the phase of the electron dipole. As a result of the high spatial resolution of the sensing the nuclear structure of molecules can be determined with low noise.

Abstract: The present disclosure provides a method of monitoring a property of a sample, such as a nanoscopic property of the sample. The method comprises the steps of providing a quantum probe having a quantum state and exposing the quantum probe to the sample in a manner such that the property of the sample, in the proximity of the quantum probe, affects quantum coherence of the quantum probe. The method also comprises detecting a rate of quantum decoherence of the quantum probe to monitor the property of the sample. Further the present disclosure provides an apparatus for monitoring a property of a sample.

Abstract: The present disclosure provides a method of monitoring a property of a sample, such as a nanoscopic property of the sample. The method comprises the steps of providing a quantum probe having a quantum state and exposing the quantum probe to the sample in a manner such that the property of the sample, in the proximity of the quantum probe, affects quantum coherence of the quantum probe. The method also comprises detecting a rate of quantum decoherence of the quantum probe to monitor the property of the sample. Further the present disclosure provides an apparatus for monitoring a property of a sample.

Abstract: The correction of errors in the transport and processing of qubits makes use of logical qubits made up of a plurality of physical qubits. The process takes place on a spatial array of physical qubit sites arranged with a quasi-2-dimensional topology having a first line of physical qubit sites and second line of physical qubit sites, where the first and second lines are arranged in parallel, with the sites of the first line in registration with corresponding sites in the second line. Between the first and second lines of physical qubit sites are a plurality of logic function gates, each comprised of a first physical qubit gate site associated with a first physical qubit site in the first line, and a second physical qubit gate site associated with the physical qubit site in the second line that corresponds to the first physical qubit site.

Abstract: This invention concerns quantum error correction, that is the correction of errors in the transport and processing of qubits, by use of logical qubits made up of a plurality of physical qubits. The process takes place on a spatial array of physical qubit sites arranged with a quasi-2-dimensional topology having a first line of physical qubit sites and second line of physical qubit sites, where the first and second lines are arranged in parallel, with the sites of the first line in registration with corresponding sites in the second line. Between the first and second lines of physical qubit sites are a plurality of logic function gates, each comprised of a first physical qubit gate site associated with a first physical qubit site in the first line, and a second physical qubit gate site associated with the physical qubit site in the second line that corresponds to the first physical qubit site.

Abstract: This invention concerns quantum computers in which the qubits are closed systems, in that the particle or particles are confined within the structure. A “site” can be produced by any method of confining an electron or other quantum particle, such as a dopant atom, a quantum dot, a cooper pair box, or any combination of these. In particular the invention concerns a closed three-site quantum particle system. The state in the third site is weakly coupled by coherent tunnelling to the first and second states, so that the third state is able to map out the populations of the first and second states as its energy is scanned with respect to the first and second states. In second and third aspects it concerns a readout method for a closed three-state quantum particle system.