Disclosed is a method of generating atomic spin orientation in an atomic ensemble. The method includes providing a steady magnetic field (5) to the atomic ensemble to cause a Zeeman splitting within first and second manifolds of the ground state of the atomic energy levels of the atomic ensemble. The method includes pumping the atomic ensemble with an electromagnetic optical radiation beam, the beam being detuned from a transition involving the first manifold such that a majority of the atomic population of the first manifold in the atomic ensemble is transferred from the first manifold into a magnetic Zeeman sublevel of the second manifold. A system for generating an atomic spin orientation in a 15 atomic ensemble is also disclosed.

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring a static magnetic field at positions of the optically pumped magnetometers, and a nulling coil for canceling the static magnetic field; an MRI apparatus including a permanent magnet, a gradient magnetic field coil, a transmission coil, and a receive coil for detecting a nuclear magnetic resonance signal; and a control device that, when measuring the brain's magnetic field, controls a current to be supplied to the nulling coil based on measured values of the magnetic sensors and operates so as to cancel a static magnetic field at the position of each of the optically pumped magnetometers and, when measuring an MR image, controls the gradient magnetic field by controlling a current to be supplied to the gradient magnetic field coil and generates an MR image based on an output of the receive coil.

The present disclosure relates to a pH-sensor for determining and/or monitoring a pH value of a medium, having a sensor unit with a wall in contact with the medium, and at least one pH-sensitive material, which has at least one spin state that changes as a function of a pH value. The at least one pH-sensitive material is arranged in or on a region of the wall in such a way that the at least one spin state is subjected to a change in the pH value of the medium. The pH-sensor also includes a spin-sensitive unit, which is configured to detect a variable associated with the at least one spin state, wherein the spin-sensitive unit is arranged in an environment of the at least one pH-sensitive material such that the spin-sensitive unit is subjected to a change in the spin state of the at least one pH-sensitive material.

A magnetic field gradiometer for determining a magnetic field gradient includes at least one excitation light source for emitting excitation light, and two spatially spaced-apart measuring areas for magnetic field measurement. Color centers in diamond are arranged in the two measuring areas. The color centers emit fluorescent light upon excitation using the excitation light. The magnetic field gradiometer further includes at least one microwave emitter for applying at least one microwave field to the spatially spaced-apart measuring areas, two detectors for detecting the fluorescent light from the two spatially spaced-apart measuring areas, and an evaluator for determining the magnetic field gradient based on the fluorescent light detected by the two detectors. The two measuring areas are configured as freestanding measuring waveguides of a common diamond crystal. The diamond crystal is used as a substrate for the measuring waveguides.

A system for positioning and maintaining a position of a reference sensor around a magnetoencephalography helmet. The system includes an arch comprising at least one fixing branch for fixing the arch to an MEG helmet, a support plate on which the branch is fixed, a sensor support post fixed to the support plate of the arch; and a locking component for fixing the reference sensor to the post in at least one position defining the position with respect to an MEG helmet.

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring geomagnetic field at positions of the optically pumped magnetometers, magnetic sensors for measuring a fluctuating magnetic field at the positions of the optically pumped magnetometers, nulling coils for cancelling the geomagnetic field, and an active shield coil for cancelling the fluctuating magnetic field; an MRI apparatus including nulling coils for applying a static magnetic field and a gradient magnetic field, a transmission coil, and a receive coil; and a control device that, when measuring a brain's magnetic field, controls currents supplied to the nulling coils and the active shield coil based on measured values of the magnetic sensors and, when measuring an MR image, controls the static magnetic field and the gradient magnetic field by controlling currents supplied to the nulling coils and generates an MR image from an output of the receive coil.

A sensor device for magnetic field measurement using optical magnetic resonance measurement (ODMR) includes a sensor device for magnetic field measurement using ODMR, including a diamond having a plurality of nitrogen defects, a laser emitter, a photodetector, and a circuit board. The laser emitter is designed for the fluorescence excitation of the nitrogen defects, and the photodetector is designed to receive fluorescence radiation of the nitrogen defects. The circuit board has a plurality of layers comprising at least one inner layer; the laser emitter is disposed on an upper face of the circuit board; the photodetector is disposed on a lower face of the circuit board; the diamond is disposed in the interior of the circuit board in the plane of extension of the at least one inner layer; and at least one of the layers has current-carrying structures designed to produce a homogeneous magnetic field which is oriented perpendicularly to the layers of the circuit board and which permeates the diamond.

A small volume optoelectronic chip contains an LED chip with a diamond having nitrogen-vacancy centers embedded therein. The LED chip generates light having a first wavelength, and the diamond with nitrogen-vacancy centers generates light having a second wavelength after excitement with light having the first wavelength. The diamond may also be on or adjacent the LED.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

In a measurement using a quantum sensor, the range of measurable physical quantities is increased while maintaining sensor sensitivity. A measuring device (10) comprises an irradiation unit (2) that irradiates a quantum sensor element (1) with electromagnetic waves for operating an electron spin state of the quantum sensor element (1) that changes due to interaction (8) with a measurement target (9), in a pulse sequence in which a time ? between n/2 pulses is a variable value; and a physical quantity measuring unit (3) that calculates a physical quantity of the measurement target based on the electron spin state after the interaction with the measurement target (9).