Systems and methods of quantum sensing include obtaining information regarding a target signal in electronic spin states of quantum defects in an ensemble of quantum defects, mapping the information regarding the target signal from the electronic spin states of the quantum defects to corresponding nuclear spin states associated with the quantum defects, applying a light pulse to the ensemble of quantum defects to reset the electronic spin states of the quantum defects, and repeating a readout stage a plurality of times within a readout duration. The readout stage includes mapping the information regarding the target signal back from the nuclear spin states to the corresponding electronic spin states and applying a data acquisition readout pulse to optically measure the electronic spin states of the quantum defects.

A magnetic measuring device includes: a determination part configured to identify four maximum inclination points in an average value in a visual field of a light detection magnetic resonance spectrum and configured to determined a degree of decrease in relative fluorescence intensity and a microwave frequency at each of the maximum inclination points; a setting part configured to set a reference decrease degree of the relative fluorescence intensity in a predetermined area and configured to set operating point frequency initial values at four points at which the reference decrease degree is achieved, near the microwave frequencies at the respective maximum inclination points; a frequency update part configured to update operating point frequencies at the four points; and a frequency correction part configured to input the updated operating point frequencies to a microwave oscillator as corrected operating point frequencies.

A magnetometer includes an electron spin defect body including a plurality of lattice point defects. A microwave field transmitter is operable to apply a microwave field to the electron spin defect body. An optical source is configured to emit input light of a first wavelength that excites the plurality of lattice point defects of the electron spin defect body from a ground state to an excited state. A first optical fiber has an input end optically coupled to the optical source and an output end. The output end is attached to a first face of the electron spin defect body and is arranged to direct the input light into the first face of the electron spin defect body. A second optical fiber has an output end and an input end. A photodetector is optically coupled to the output end of the second optical fiber.

The present disclosure relates to the technical field of current sensors, and provides a fiber-optic current transformer based on nitrogen-vacancy (NV) centers in diamond, and a measurement method. The fiber-optic current transformer based on NV centers in diamond includes a device for laser light excitation and reflected light reception and analysis, a diamond NV center probe, a magnetic concentrator, and a microwave excitation device. The fiber-optic current transformer based on NV centers in diamond includes three measurement methods: an all-optical measurement method, a non-all-optical measurement method, and a measurement method combining the all-optical measurement method and the non-all-optical measurement method. A sensor in the present disclosure has advantages of a simple structure, strong practicability, resistance to external interference, and strong robustness.

The present application discloses methods and apparatus for detecting a complex including an analyte that include contacting a sample in a solution with a population of functionalized beads of a first type, which are magnetic functionalized beads and are functionalized to include a first moiety that associates with an analyte under suitable conditions, contacting the sample solution with a population of functionalized beads of a second type, which are functionalized to include a second moiety that associates with the analyte under suitable conditions, contact resulting in formation of a complex including one of the first type of functionalized bead, the analyte, and one of the second type of functionalized bead, and detecting the complex including the analyte by detecting magnetic fields produced by the magnetic functionalized bead and by detecting the functionalized bead of the second type associated with the analyte in the complex.

An ODMR member is arranged in a measurement target AC magnetic field. A coil applies a magnetic field of a microwave to the ODMR member. A high frequency power supply causes the coil to conduct a current of the microwave. An irradiating device irradiates the ODMR member with light. A light receiving device detects light that the ODMR member emits. A measurement control unit performs a predetermined DC magnetic field measurement sequence at a predetermined phase of the measurement target AC magnetic field, and in the DC magnetic field measurement sequence, controls the high frequency power supply and the irradiating device and thereby determines a detection light intensity of the light detected by the light receiving device. A magnetic field calculation unit calculates an intensity of the measurement target AC magnetic field on the basis of the predetermined phase and the detection light intensity.

Disclosed herein is a sensor chip for parallelized magnetic sensing of a plurality of samples, a system for parallelized magnetic sensing of a plurality of samples and a method for probing a plurality of samples using optically addressable solid-state spin systems. The sensor chip comprises an optically transparent substrate comprising a plurality of optically addressable solid-state spin systems arranged in a plurality of sensing regions in a surface layer below a top surface of the substrate. The sensor chip further comprises a plurality of sample sites, wherein each sample site is arranged above a respective sensing region. The sensor chip has a light guiding system configured to provide an optical path through the substrate connecting each of the sensing regions.

Sensing the electric or strain field experienced by a sample containing a crystal host comprising of solid state defects under a zero-bias magnetic fields can yield a very sensitive measurement. Sensing is based on the spin states of the solid-state defects. Upon absorption of suitable microwave (and optical) radiation, the solid-state defects emit fluorescence associated with hyperfine transitions. The fluorescence is sensitive to electric and/or strain fields and is used to determine the magnitude and/or direction of the field of interest. The present apparatus is configured to control and modulate the assembly of individual components to maintain a zero-bias magnetic field, generate an Optically Detected Magnetic Resonance (ODMR) spectrum (with or without optical excitation) using appropriate microwave radiation, detect signals based on the hyperfine state transitions that are sensitive to electric/strain fields, and to quantify the magnitude and direction of the field of interest.

A sensor includes two magnetic sensors detecting a magnetic field around an object, and outputting at least one of a magnetic field signal and a temperature signal, an optical system emitting the excitation light to the two magnetic sensors, and a processor calculating a difference between a magnetic fields corresponding to the magnetic field signal detected by the two magnetic sensors, wherein each of the magnetic sensors includes an element disposed around the object and having color centers, an antenna radiating a microwave magnetic field to the element, an optical sensor detecting an intensity of a fluorescence generated by the element, and outputting an intensity signal, and a controller calculating at least one of a magnetic field and temperature around the measurement object, and output at least one of a magnetic field signal indicating the calculated magnetic field and a temperature signal indicating the calculated temperature to the processor.

A substrate 1 includes a color center excited by excitation light, and at least a pair of reflection members 21a, 21b are arranged with gaps from the substrate 1. The substrate 1 causes the excitation light entering the substrate 1 to exit through its surfaces without reflection, and the reflection members 21a, 21b cause the exited excitation light to reflect at the reflection surface 21-1 or 21-2 and enter the substrate 1, and cause the excitation light to repeatedly enter and exit the substrate 1 and thereby pass through the substrate 1 only a predetermined number of times. Here, the irradiating device 4 emits the excitation light such that the excitation light is incident to the reflection surface 21-1 or 21-2 with an angle perpendicular to one axis among two axes of the reflection surface 21-1 or 21-2 and with a predetermined slant angle from the other axis.