A method, system and device for sensing a physical condition in a crystal lattice

Abstract

A method, device and system for sensing physical conditions in a lattice may include at least one diamond having a lattice with one or more point defects. Embodiments of the invention may control a light source to emit a pulse of light at an appropriate frequency to excite the point defects into fluorescence of photons, thereby initializing their energy state at a ground state. Embodiments may transmit an EM signal at a predefined band of microwave frequency through the at least one diamond; receive the EM signal from the at least one diamond by at least one receiver; and obtain a reading of the received EM signal from the at least one receiver. Based on the reading, Embodiments may calculate absorption of the transmitted EM signal in the at least one diamond and analyze this absorption, to compute a physical condition of the point defects in the diamond.

Description

A METHOD, SYSTEM AND DEVICE FOR SENSING A PHYSICAL CONDITION IN A CRYSTAL LATTICECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Israeli Patent Application No. 312136, filed April 14, 2024 and titled “A METHOD, SYSTEM AND DEVICE FOR SENSING A PHYSICAL CONDITION IN A CRYSTAL LATTICE”, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of material science. More specifically, the present invention relates to sensing a physical condition in a crystal lattice.BACKGROUND OF THE INVENTION

[0003] Point defects are atomic-scale changes in crystal lattice, which are extensively studied in the field of material science as exhibiting unique optical and magnetic properties, making them valuable for various applications in quantum sensing, quantum computing, and nanoscale metrology. Prominent examples of point defects include Nitrogen- Vacancy (NV) centers in a diamond lattice structure, consisting of a Nitrogen atom adjacent to a missing carbon atom, referred to herein as a “vacancy”.

[0004] Currently available technology for studying NV centers includes Optically Detected Magnetic Resonance (ODMR), which is a spectroscopic technique that involves measuring changes in the fluorescence emission of NV centers in response to an applied magnetic field and microwave radiation.

[0005] NV centers in diamond have become a focal point in quantum technology research due to unique electronic structure and optical properties, which allow for quantum state manipulation at room temperature. Reference is made to Fig. 1, which is a schematic drawing, depicting transition of point defects (e.g., NV centers) between atomic energy levels, as performed in a typical ODMR process, as known in the art.

[0006] As shown in Fig. 1, electron energy levels of an NV center feature a ground state (3A2), an excited state (3E), and a metastable state (1 A 1). The ground 3A2 and excited 3E energy states are spin-triplet states, meaning they include three spin configurations, or spinstates, denoted ms = 0, +1, -1. The metastable 1A1 state is a non-radiative, spin- singlet statethat plays an important role in spin polarization and readout. Transitions between the triplet and singlet states are spin-selective.

[0007] An NV center may initially reside at ground state 3A2. When illuminated at an appropriate wavelength (e.g., green light around 532 nm), the NV center may absorb photons and become excited to higher energy states, e.g., transfer from the 3A2 state to the 3E state.

[0008] The excited NV centers emit fluorescence photons as they return to their ground state 3A2. The fluorescence emission from NV centers can be detected using photodetectors, providing information about their presence and spatial distribution in the diamond lattice.

[0009] In the presence of an external magnetic field, the energy levels of the NV centers in the spin-states ms= 0, -1, 1 split due to the Zeeman effect. The energy level splitting depends on the orientation and strength of the magnetic field (denoted as ‘B’).

[0010] Currently available ODMR systems may probe the magnetic properties of NV centers by applying microwave radiation at various frequencies while monitoring the fluorescence emission. The microwave frequency is swept across a range of values, including the resonant frequency corresponding to the energy level splitting induced by the magnetic field.

[0011] For example, ODMR systems may be used to manipulate and read spin polarization: An NV center may absorb microwave radiation at the point of dipole spin resonance, i.e., when the frequency of the applied microwave radiation precisely matches the frequency needed for electron spins to transition between their energy levels. External factors, such as temperature, stress, electric fields, or magnetic fields, can alter the energy levels of the electron spins, thereby changing the resonance frequency necessary for absorption.

[0012] Illuminating NV centers with green light not only excites the center to the 3E excited state but also preferentially transfers electrons from the ms=±l spin-states of the 3E excited state to the metastable state 1A1, from which they decay preferentially to the ms = 0 spinstate of ground state 3A2. This process, known as optical pumping, effectively initializes the NV centers into the ms=0 spin-state of ground state 3A2, readying it for quantum operations.

[0013] Once initialized, the spin-state of an electron in ground state 3A2 can be coherently manipulated using microwave radiation. By applying microwave pulses resonant with the energy difference between the ms= 0 spin-state and the ms = ±1 spin-states, it's possible to induce transitions between these spin-states, effectively manipulating the qubit.

[0014] ODMR may exploit the difference in fluorescence intensity between the ms = 0 and ms = ±1 spin-states, to perform a readout of the NV center's spin-state: The ms = 0 spin-state of excited state 3E has a higher probability of returning to ground state 3A2 via radiative decay, emitting a photon (red fluorescence), whereas the ms = ±1 spin-states of excited state 3E are more likely to undergo non-radiative decay via the metastable state 1A1. By detecting the intensity of the emitted fluorescence, the spin state of the NV center can be determined.

[0015] The representation of fluorescence intensity of NV centers as a function of frequency of applied microwave radiation, given specific values of surrounding conditions (temperature, pressure, magnetic and electric fields) is referred to herein as the “ODMR spectrum”. Reference is also made to Figs. 2A, 2B and 2C which depict ODMR spectra in different conditions, as known in the art.

[0016] As shown in Figs. 2A and 2B, at certain microwave frequencies corresponding to the energy level splitting of the NV centers, the fluorescence emission intensity changes significantly. These frequencies are manifested as dips (decreased fluorescence intensity) or peaks (increased fluorescence intensity) in the ODMR spectrum, indicating the presence of specific magnetic field strengths or orientations that affect the NV center fluorescence.

[0017] The depicted dips in NV center fluorescence occur due to interaction between the microwave radiation and the NV centers’ spin states. Such interactions may cause some NV centers not to return to their ground state 3A2 by fluorescing a photon corresponding to the energy gap between 3E and 3A2, but rather return to 3A2 via metastable state 1A1, resulting in reduced visible fluorescence manifested as the depicted dips.

[0018] The shape, position, and amplitude of the peaks or dips in the ODMR spectrum provide valuable information about the magnetic properties of the NV centers. This information includes, for example extent of the zero-field energy-level splitting, electron spin resonance frequencies, and sensitivity to magnetic fields.

[0019] Additionally, as shown in Fig. 2C, dips of the ODMR spectrum may also be affected by ambient conditions such as stress and temperature.

[0020] Researchers may therefore analyze the ODMR spectrum, to characterize, and understand the quantum behavior of the NV centers.SUMMARY OF THE INVENTION

[0021] The currently available ODMR spectrum analysis technique is an iterative process, where each iteration requires: (i) incremental modification of the applied microwavefrequency, (ii) laser-excitation of the NV centers, and (iii) reading a value of NV center fluorescence. It may be appreciated by a person skilled in the art that such an iterative process is both inaccurate, and forbiddingly long for some applications: It is inaccurate in a sense that it may exhibit inferior signal to noise (SNR) ratio, due to limited repeatability and accuracy of hardware operation between the plurality of iterations. It is forbiddingly long because each of the multitude of iterations requires readout of fluorescence pertaining to a specific microwave frequency, making the currently available ODMR spectrum analysis technique improper for real-time sensing and imaging applications.

[0022] As elaborated herein, instead of iteratively, and repetitively measuring ODMR fluorescence corresponding to a sweep of microwave radiation frequencies (e.g., as depicted in Figs. 2A, 2B, 2C), embodiments of the invention may measure and analyze the absorption of microwave radiation in a small (e.g., a single) number of measurements, using a wide bandwidth of microwave radiation frequencies, that may be appropriately selected to facilitate an intended application or measurement.

[0023] Embodiments of the invention may thereby provide several improvements in the technological field of material science:

[0024] For example, by performing a single measurement of absorption of microwave radiation in a wide band of microwave frequencies, embodiments of the invention may facilitate real-time generation and analysis of data that is equivalent to an ODMR spectrum, without requiring multiple readings of individual fluorescence values, corresponding to respective microwave frequencies. Embodiments of the invention may thereby overcome the abovementioned shortcomings of accuracy and real-time limitations inherent in currently available ODMR systems.

[0025] Implementations of the present invention may thus enable practical, real-time applications in a variety of reliant technologies, including for example, quantum sensing, quantum computing, magnetic field detection, magnetic field imaging, magnetic radar systems, and nanoscale magnetometry, to mention a few.

[0026] In another example, the broad fluorescence emission spectrum of point defects such as nitrogen-vacancy (NV) centers in diamonds, typically range from 637 nm to 800 nm. This broad range limits the sensitivity and resolution of magnetic field sensing because it overlaps with background fluorescence, reduces contrast between the NV center's signal in the presence and absence of an external magnetic field, and is subject to spectral diffusion.Additionally, the broad emission spectrum makes it difficult for currently available, fluorescence-based ODMR systems to efficiently collect and detect the fluorescence signal, leading to poor signal-to-noise ratio and reduced sensitivity in magnetic field measurements.

[0027] In contrast, embodiments of the present invention may not rely on readout of fluorescence, and are therefore not susceptible to these deficiencies.

[0028] For example, embodiments of the present invention may not rely on fluorescence readout, and therefore may not rely upon transition through state 1A1. Therefore, embodiments of the invention are less prone to noise, and may provide higher resolution in measurement (e.g., of magnetic fields), in relation to currently available ODMR-based systems.

[0029] Embodiments of the invention may include a device, and / or a system for sensing a physical condition in a lattice. Embodiments of the device may include at least one diamond, having a lattice that includes one or more point defects. Embodiments of the device may further include at least one transmitter, adapted to transmit an electromagnetic (EM) signal at a predefined band of microwave frequency, via a respective emission element, through the at least one diamond and at least one receiver, adapted to receive the EM signal from the at least one diamond, via a respective reception element.

[0030] The at least one emission element may, for example, be a transmission antenna, and the at least one reception element may, for example, be a receiver antenna. According to some embodiments, at least one of the receiver antenna and transmitter antenna may be embedded within the diamond.

[0031] Embodiments of the device may further include, or be communicatively connected to at least one controller or processor, associated with said receiver. As elaborated herein, the at least one controller or processor may be configured to compute a lattice data element, representing a physical condition of the one or more point defects in the at least one diamond, based on the received EM signal.

[0032] According to some embodiments, at least one diamond may include a single point defect, and the lattice data element may represent a physical condition of the single point defect.

[0033] Additionally, or alternatively, the at least one diamond may include an assembly of single point defects, located at a minimal predetermined distance from one another, and thelattice data element may represent a physical condition of one or more (e.g., each) of the single point defects.

[0034] For example, the physical condition may be a quantum state of the one or more point defects in the lattice of the at least one diamond: The one or more point defects may respectively represent one or more quantum bits (qubits), and the physical condition of the one or more point defects may, for example, be a spin-quantum state corresponding to a value of the respective one or more qubits. The lattice data element may thus represent a reading of qubit-data, as manifested by the spin-quantum state of the one or more qubits.

[0035] Additionally, or alternatively, the at least one controller may be further configured to control the at least one transmitter, so as to transmit an EM signal at a predetermined microwave frequency via the emission element, to affect the spin-quantum state of at least one point defect, thereby writing qubit-data into at least one respective qubit.

[0036] Additionally, or alternatively, one or more point defects may be associated with one or more respective magnetic field inductors or magnets, configured to induce a magnetic field at a location of the one or more point defects. The controller may be further configured to determine the microwave frequency based on intensity of the induced magnetic field.

[0037] Additionally, or alternatively, the physical condition may include, for example, an amplitude of a magnetic field at the one or more point defects, and a polarization of a magnetic field at the one or more point defects.

[0038] Additionally, or alternatively, the physical condition may include, for example a stress of the at least one diamond’s lattice at the one or more point defects, and / or a temperature at the one or more point defects.

[0039] According to some embodiments, the point defects may include, for example Nitrogen- Vacancy (NV) centers, Silicon- Vacancy (SV) centers, Germanium- Vacancy (GeV) centers, Led- Vacancy (PbV) centers, and Tin- Vacancy (SnV) centers.

[0040] According to some embodiments, the at least one controller may compute the lattice data element by obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal in the at least one diamond; and performing spectral analysis of the absorption data element, to compute the lattice data element.

[0041] Embodiments of the device may further include a light source (e.g., a laser source), adapted to emit light at an appropriate frequency to excite the point defects into fluorescence of photons, thereby initializing their energy state at a ground state.

[0042] The at least one controller may be configured to compute the lattice data element repeatedly, over a plurality of iterations, wherein each iteration may include the steps of: controlling the light source to initialize the point defects’ energy states at the ground state; controlling the transmitter, to transmit the EM signal through the at least one diamond; obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond; and analyzing the absorption data element, to compute the lattice data element.

[0043] The absorption data element may include, for example, a point-wise difference between a spectral distribution of the transmitted EM signal and a spectral distribution of the received EM signal.

[0044] Embodiments of the device or system may further include a calibration module, associated with the controller. The controller may be further configured to utilize the calibration module to generate a calibration table, representing a spectrum of absorption of EM frequencies, by the specific at least one diamond; and compute the lattice data element further based on the calibration table, to compensate for irregularities or impurities in the specific, at least one diamond.

[0045] For example, the calibration module may include an EM power splitter, configured to split the transmitted EM signal to a measurement path, that traverses the at least one diamond, and a reference path. The calibration module may further include phase shifter, located in the reference path, and configured to produce a delayed version of the transmitted EM signal; and a mixer module. The mixer module may be adapted to generate an EM difference signal, representing a difference between (i) the delayed version of the transmitted EM signal and (ii) the received EM signal at the reception element.

[0046] The controller may be further configured to control the phase shifter based on the EM difference signal, so as to compensate for at least one of (a) difference in EM propagation between the reference path and measurement path, and (b) phase inconsistencies in the transmitted EM signal.

[0047] Additionally, or alternatively, the at least one controller may be configured to perform spectral analysis of the EM difference signal, and generate the calibration table based on that spectral analysis.

[0048] Embodiments of the invention may further implement a magnetic imaging apparatus, that may include, or be consisted of an array of instances of the aforementioned diamond, or device. Each diamond or device instance may correspond to an image pixel. Embodiments of the invention may produce, for each instance of diamond or device, a lattice data element that represents an amplitude or polarization of a magnetic field at the point defects of that diamond or device.

[0049] Embodiments of the invention may thereby produce an image of amplitude or polarization of a magnetic field at the location of the array of the aforementioned devices.

[0050] Additionally, or alternatively, embodiments of the invention may include an RF emitter, configured to emit RF radiation. The array of instances may be configured to receive reflection of the emitted RF radiation (e.g., from surrounding objects), to produce an image of a magnetic component of the reflected RF radiation, thereby acting as a “radar” of a magnetic field.

[0051] Embodiments of the invention may include a method of sensing a physical condition in a lattice by at least one processor or controller. Embodiments of the method may include: obtaining at least one diamond having a lattice that includes one or more point defects; controlling a light source to emit a pulse of light at an appropriate frequency to excite the point defects into fluorescence of photons, thereby initializing their energy state at a ground state; transmitting an EM signal at a predefined band of microwave frequency through the at least one diamond; receiving the EM signal from the at least one diamond by at least one receiver; and obtaining a reading of the received EM signal from the at least one receiver. Based on this reading, employing the at least one controller or processor to calculate an absorption data element, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond; and analyzing the absorption data element by the at least one controller or processor, to compute a lattice data element representing a physical condition of the one or more point defects in the diamond.BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as toorganization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0053] Fig. 1 is a schematic drawing, depicting transition of point defects’ atomic energy levels in a typical ODMR process, as known in the art;

[0054] Figs. 2A, 2B and 2C are graphs which depict ODMR spectra in different conditions, as known in the art;

[0055] Fig. 3 is a block diagram, depicting a computing device which may be included in a system or device for sensing a physical condition in a crystal lattice, according to some embodiments of the invention;

[0056] Fig. 4 is a block diagram, depicting a system, or device for sensing a physical condition in a crystal lattice, according to some embodiments of the invention;

[0057] Figs. 5A and 5B are isometric drawings showing examples for implementation of components of a sensor that may be included in the system or device for sensing a physical condition in a crystal lattice, according to some embodiments of the invention;

[0058] Fig. 6 is a schematic diagram, depicting a sensor that may be included in a system, or device for sensing a physical condition in a crystal lattice, according to some embodiments of the invention;

[0059] Fig. 7A is a schematic diagram, depicting an isometric view of components of an array of sensors, that may be included in a system, or device for sensing a physical condition in a crystal lattice, according to some embodiments of the invention;

[0060] Fig. 7B and 7C are schematic diagrams, depicting components of the array of Fig. 7A, according to some embodiments of the invention; and

[0061] Fig. 8 is a flow diagram, depicting a method of sensing a physical condition in a crystal lattice, according to some embodiments of the invention.

[0062] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0063] One skilled in the art will realize the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0064] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated.

[0065] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and / or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and / or transforms data represented as physical (e.g., electronic) quantities within the computer’s registers and / or memories into other data similarly represented as physical quantities within the computer’s registers and / or memories or other information non-transitory storage medium that may store instructions to perform operations and / or processes.

[0066] Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term “set” when used herein may include one or more items.

[0067] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of thedescribed method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently.

[0068] Reference is now made to Fig. 3, which is a block diagram depicting a computing device, which may be included within an embodiment of a system or device for sensing a physical condition in a crystal lattice, according to some embodiments.

[0069] Computing device 1 may include a processor or controller 2 that may be, for example, a central processing unit (CPU) processor, a chip or any suitable computing or computational device, an operating system 3, a memory 4, executable code 5, a storage system 6, input devices 7 and output devices 8. Processor 2 (or one or more controllers or processors, possibly across multiple units or devices) may be configured to carry out methods described herein, and / or to execute or act as the various modules, units, etc. More than one computing device 1 may be included in, and one or more computing devices 1 may act as the components of, a system according to embodiments of the invention.

[0070] Operating system 3 may be or may include any code segment (e.g., one similar to executable code 5 described herein) designed and / or configured to perform tasks involving coordination, scheduling, arbitration, supervising, controlling or otherwise managing operation of computing device 1, for example, scheduling execution of software programs or tasks or enabling software programs or other modules or units to communicate. Operating system 3 may be a commercial operating system. It will be noted that an operating system 3 may be an optional component, e.g., in some embodiments, a system may include a computing device that does not require or include an operating system 3.

[0071] Memory 4 may be or may include, for example, a Random- Access Memory (RAM), a read only memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), a double data rate (DDR) memory chip, a Flash memory, a volatile memory, a nonvolatile memory, a cache memory, a buffer, a short term memory unit, a long term memory unit, or other suitable memory units or storage units. Memory 4 may be or may include a plurality of possibly different memory units. Memory 4 may be a computer or processor non-transitory readable medium, or a computer non-transitory storage medium, e.g., a RAM. In one embodiment, a non-transitory storage medium such as memory 4, a hard disk drive, another storage device, etc. may store instructions or code which when executed by a processor may cause the processor to carry out methods as described herein.

[0072] Executable code 5 may be any executable code, e.g., an application, a program, a process, task, or script. Executable code 5 may be executed by processor or controller 2 possibly under control of operating system 3. For example, executable code 5 may be an application that may sense a physical condition in a crystal lattice, as further described herein. Although, for the sake of clarity, a single item of executable code 5 is shown in Fig. 3, a system according to some embodiments of the invention may include a plurality of executable code segments similar to executable code 5 that may be loaded into memory 4 and cause processor 2 to carry out methods described herein.

[0073] Storage system 6 may be or may include, for example, a flash memory as known in the art, a memory that is internal to, or embedded in, a micro controller or chip as known in the art, a hard disk drive, a CD-Recordable (CD-R) drive, a Blu-ray disk (BD), a universal serial bus (USB) device or other suitable removable and / or fixed storage unit. Data pertaining to a crystal lattice may be stored in storage system 6 and may be loaded from storage system 6 into memory 4 where it may be processed by processor or controller 2. In some embodiments, some of the components shown in Fig. 3 may be omitted. For example, memory 4 may be a non-volatile memory having the storage capacity of storage system 6. Accordingly, although shown as a separate component, storage system 6 may be embedded or included in memory 4.

[0074] Input devices 7 may be or may include any suitable input devices, components, or systems, e.g., a detachable keyboard or keypad, a mouse and the like. Output devices 8 may include one or more (possibly detachable) displays or monitors, speakers and / or any other suitable output devices. Any applicable input / output (VO) devices may be connected to Computing device 1 as shown by blocks 7 and 8. For example, a wired or wireless network interface card (NIC), a universal serial bus (USB) device or external hard drive may be included in input devices 7 and / or output devices 8. It will be recognized that any suitable number of input devices 7 and output device 8 may be operatively connected to Computing device 1 as shown by blocks 7 and 8.

[0075] A system according to some embodiments of the invention may include components such as, but not limited to, a plurality of central processing units (CPU) or any other suitable multi-purpose or specific processors or controllers (e.g., similar to element 2), a plurality of input units, a plurality of output units, a plurality of memory units, and a plurality of storage units.

[0076] Reference is now made to Fig. 4, which depicts a system or device 10 for sensing a physical condition in a crystal lattice, according to some embodiments.

[0077] The terms “system” and “device” may be used herein interchangeably, according to context. For example, system 10 may be referred to as a “device” when modules of system 10 (e.g., elements 100, 200, 300 and 400) reside within a single physical entity or contraption. In a complementary manner, system 10 may be referred to as a “system” when one or more modules (e.g., evaluation module 300) are communicatively connected to, but reside within a separate physical entity (e.g., a separate computing device 1) from other modules (e.g., 100, 200, 400) of system 10.

[0078] According to some embodiments, system 10 may be implemented as a software module, a hardware module, or any combination thereof. For example, system 10 may be or may include a computing device such as element 1 of Fig. 3, and may be adapted to execute one or more modules of executable code (e.g., element 5 of Fig. 3) to sense a physical condition in a crystal lattice, as further described herein.

[0079] As shown in Fig. 4, dashed arrows may represent physical elements (e.g., radiation, magnetic field, electrical current, and the like) that may be transferred among modules of system 10. Additionally, solid arrows may represent flow of one or more data elements to and from system 10, and / or among modules of system 10. Some arrows have been omitted in Fig. 4 for the purpose of clarity.

[0080] According to some embodiments, device 10 may be, or may include a sensor module 100, adapted to sense a physical condition in a crystal lattice, as elaborated herein.

[0081] According to some embodiments, sensor module 100 may include at least one diamond 120 having a lattice that includes one or more point defects 120PD. For example, the one or more point defects 120PD maybe, or may include Nitrogen- Vacancy (NV) centers as point defects 120PD, Silicon- Vacancy (SV) centers as point defects 120PD, Germanium- Vacancy (GeV) centers as point defects 120PD, Led-Vacancy (PbV) centers as point defects 120PD, Tin-Vacancy (SnV) centers as point defects 120PD, and the like.

[0082] sensor module 100 may further include at least one transmitter 110TX and at least one respective receiver 130RX.

[0083] The at least one transmitter 110TX may be adapted to transmit an electromagnetic (EM) signal 110RF at a predefined band of microwave frequency, via a respective emission element 115AN, through the at least one diamond 120. The at least one receiver 130RX maybe adapted to receive the transmitted EM signal 110RF from the at least one diamond 120, via a respective reception element 135 AN.

[0084] Reference is also made to Figs. 5A and 5B, which are isometric drawings showing examples for implementation of sensor 100 (e.g., same as sensor 100 of Fig. 4), that may be included in system 10, or device 10 (as in Fig. 4), for sensing a physical condition in a crystal lattice, according to some embodiments of the invention. As elaborated herein, sensor 100 may be regarded as a tunable dielectric absorber, in a sense that it may sense a configurable change in EM radiation absorption by diamond 120, as a function of applied conditions such as magnetic field, electric field, heat and stress.

[0085] Fig. 5A presents a first optional implementation of sensor 100, that may be referred to as a “Waveguide” configuration.

[0086] As shown in Fig. 5A, emission element 115AN may be a transmission antenna 115AN, configured to transmit EM radiation via diamond 120, and reception element 135 AN may be a receiver antenna 135 AN, adapted to receive EM radiation from diamond 120. In this context, the terms emission element 115AN and transmission antenna 115AN may be used interchangeably, and the terms reception element 135AN and receiver antenna 135AN may be used interchangeably.

[0087] As shown in Fig. 5A, at least one antenna (e.g., of the at least one receiver antenna 135AN and at least one transmitter antenna 115AN) may be juxtaposed to the at least one diamond 120. Additionally, or alternatively, at least one antenna 115AN / 135AN may be embedded within the at least one diamond 120.

[0088] Additionally, the medium of EM radiation (e.g., the at least one diamond 120) may (or may not) be encased within a metal coating, as in a radio-frequency (RF) waveguide configuration, hence the term “waveguide configuration”.

[0089] Fig. 5B presents a second optional implementation of sensor 100, that may be referred to as a “patch antenna” configuration.

[0090] As shown in Fig. 5B, emission element 115AN and reception element 135AN may be arranged on two ends of a common conducting element, denoted herein as a signal plane 124. Signal plane 124 may, for example, be implemented by a conducting wire or microstrip, juxtaposed to the at least one diamond 120. Additionally, sensor 100 may include a second conducting element that may be referred to as a ground plane 126. Ground plane 126 mayinclude a metallic surface, juxtaposed to the at least one diamond 120 on an opposite side to that of signal plane 124.

[0091] Signal plane 124 and ground plane 126 may thereby jointly form a patch antenna, as commonly referred to in the art, where ground plane 126 may serve as a reference, or a ground for an electric signal at the signal plane 124. Sensor 100 may be fed an electric signal at one end (e.g., at emission element 115AN) of signal plane 124, to transmit EM radiation 110RF via diamond 120. EM radiation 110RF may be reflected from ground plane 126 via diamond 120, and may affect the electric signal at the location of the reception element 135AN end of signal plane 124. As elaborated herein, device 10 may analyze the electrical signal at the reception element 135 AN to determine the effect of diamond 120 on EM radiation 110RF, and subsequently compute a lattice data element 300L representing a physical condition of the one or more point defects 120PD in diamond 120.

[0092] The predefined band of microwave frequency may be selected according to a specific intended application of system 10, so as to allow system 10 to determine a value of a physical condition of one or more point defects 120PD in diamond 120 in a single measurement, e.g., without sweeping through a plurality of frequencies, or frequency bands. In other words, intelligent selection of an appropriate microwave frequency band, according to specific application requirements may allow embodiments of the invention to render frequency sweeps redundant, avoid measurement inaccuracies due to repeatability errors, and reduce inaccuracies due to the effect of point defects 120PD quantum state coherence time.

[0093] Pertaining to the example of Fig. 2: In order to locate and characterize the dips in an ODMR spectrum, currently available, fluorescence-based ODMR systems should sweep through frequencies between 2860 and 2880 MHz (e.g., going through each circle in Fig. 2) in a multitude of measurements. Instead of doing so, embodiments of the invention may achieve the same result in a small number (e.g., a single) of measurements by defining the band of microwave frequency to be in the order (e.g., between X101and X10) of the bandwidth of interest (e.g., the bandwidth of the depicted dip - approx. 100MHz).

[0094] As shown in Fig. 4, system 10 may include an evaluation module 300. Evaluation module 300 may include, or may be implemented by a computing device such as computing device 1 of Fig. 3. Evaluation module 300 may include, or may be associated with at leastone processor or controller such as controller 2 of Fig. 3. Controller 2 may be associated with, or communicatively connected to receiver 130RX.

[0095] As elaborated herein, evaluation module 300 may be configured to compute a lattice data element 300L, representing a physical condition or property of the one or more point defects 120PD in the at least one diamond 120, based on the received EM signal 130RF.

[0096] For example, the at least one diamond 120 may include a single point defect 120PD, and the lattice data element may represent a value of a physical condition of the single point defect.

[0097] Additionally, or alternatively, the at least one diamond 120 may include an assembly of single point defects, located at a minimal predetermined distance from one another, so as to minimize (e.g., reduce below a predetermined value) the mutual effect of each point defect on the coherence time of all other point defects in the lattice of diamond 120. In such embodiments, lattice data element 300E may represent a value of a physical condition or property of one or more (e.g., each) of the single point defects 120PD in the lattice of diamond 120.

[0098] Additionally, or alternatively, the at least one diamond 120 may include one or more groups or clusters of point defects 120PD, having unknown physical locations and / or mutual distances. In such embodiments, lattice data element 300E may represent a value of a physical condition or property of the one or more (e.g., each) of the groups or clusters of point defects 120PD in the lattice of diamond 120.

[0099] As used herein, a “physical condition” of one or more point defects 120PD may include any combination of inherent, and / or induced properties and / or quanta pertaining to, or measured at one or more point defects 120PD of diamond 120.

[0100] For example, lattice data element 300E may represent a value of a physical condition such as a quantum state (denoted 340QS) of the one or more point defects 120PD. In this context, a “quantum state” 340QS may refer, for example to a spin quantum state, e.g., a magnetic spin of an electron in one or more point defects 120PD. In another example, the term “quantum state” 340QS may refer to an energy level of an electron in one or more point defects 120PD.

[0101] Additionally, or alternatively, the term “physical condition” may further relate to a measurement of one or more physical conditions of one or more point defects 120PD indiamond 120, which may be derived from, or obtained by calculation of quantum state 340QS.

[0102] For example, lattice data element 300L may represent a value of temperature (denoted 350T) and / or stress (denoted 370S), at the one or more point defects 120PD.

[0103] In another example, lattice data element 300L may represent a value of a magnetic field amplitude and / or polarization (denoted 360B) at the one or more point defects 120PD.

[0104] In yet another example, lattice data element 300L may represent a value of an electric field amplitude and / or polarization (denoted 38OE) at the one or more point defects 120PD.

[0105] It may be appreciated that lattice data element 300L may represent any combination of the abovementioned physical condition values.

[0106] As shown in Fig. 4, evaluation module 300 may include an absorption calculation module 310, configured to obtain (e.g., via wired, or wireless communication) a reading of the received EM signal 130RF from the at least one receiver 130RX.

[0107] Based on the EM signal 130RF reading and transmitted EM radiation 110TX, absorption calculation module 310 may calculate an absorption data element 310AB, representing absorption of the EM signal 110RF in the at least one diamond 120.

[0108] In other words, at an initial level of generalization and accuracy, absorption data element 310AB may include, or be viewed as point- wise difference between a spectral distribution of EM signal 11 ORF and a spectral distribution of the received EM signal 130RF.

[0109] Absorption data element 310AB may, for example, include a data structure (e.g., a vector), where each entry may pertain to a specific frequency in the microwave range, and represent a percentage of EM radiation absorption in that frequency.

[0110] Additionally, or alternatively, device 10 may include a differential detector module 400, adapted to eliminate the effect of perturbations in the phase and amplitude of the transmitted EM radiation 110TX on absorption data element 310AB.

[0111] Differential detector 400 may include an EM power splitter 410 (drawn in Fig. 4 as part of sensor 100). EM power splitter 410 may be configured to split the transmitted EM signal 110RF to a measurement path 110RF1, that traverses the at least one diamond 120, and to a reference path 110RF2.

[0112] Differential detector 400 may further include a phase shifter module 420, located in the reference path 110RF2, and a mixer module 430. Phase shifter module 420 may be configured to produce a delayed version 420RF of the transmitted EM signal 110TX. Mixer module 430 may generate an EM difference signal 430D, representing a difference between (i) the delayed version 420RF of the transmitted EM signal 110RF and (ii) the received EM signal 130RF at the reception element 135AN.

[0113] For example, Phase shifter module 420 may produce EM signal 420RF as a 180 degree phase shift transmitted EM signal 110TX, causing mixer 430 to generate EM difference signal 430D as a product of a destructive interference of EM signal 11 ORF, thereby eliminating the effect of perturbations in the phase and amplitude of the transmitted EM radiation 110TX. Absorption calculation module 310 may thereby calculate an absorption data element 310AB that is devoid of perturbations in the phase and amplitude of the transmitted EM radiation 110TX, based on the EM signal 130RF reading and transmitted EM radiation 110TX (e.g., based on differential signal 430D).

[0114] Additionally, or alternatively, evaluation module 300 may control phase shifter 420 in real-time, or near real-time, based on (e.g., in order to minimize) EM difference signal 430D. In other words, controller 2 of evaluation module 300 may be configured to control phase shifter 420 based on EM difference signal 430D, so as to compensate for at least one of (a) difference in EM propagation between the reference path 110RF2 and measurement path 110RF1, and (b) phase inconsistencies (e.g., jitters) in the EM signal 110RF transmitted by transmitter 110TX.

[0115] Additionally, or alternatively, and as elaborated herein, the calculation of the absorption data element 310AB may require a prerequisite calibration process, by which a calibration table calculation module 320 may generate a diamond- specific calibration table 320T.

[0116] According to some embodiments, system 10 may include a calibration module, or calibration stage, configured to generate a calibration table 320T, representing a spectrum of absorption of EM frequencies, by a specific at least one diamond 120. System 10 may then compute lattice data element 300L further based on the calibration table 320T, to compensate for irregularities in the specific, at least one diamond.

[0117] Calibration table 320T may be a data structure (e.g., a table), dedicated to a specific sensor 100 or diamond 120. Each entry of table 320T may pertain to a specificfrequency in the microwave range, and to unique environmental conditions such as temperature, and / or stress in which diamond 120 may reside. Each entry of table 320T may represent a percentage of EM radiation absorption in the relevant EM frequency and environmental conditions, while the point defects 120PD are at the ms=0 spin- state of ground state 3A2, as explained herein.

[0118] In other words, calibration table 320T may be regarded as a ground-state “snapshot” of the overall effect of impurities in diamond 120 (e.g., Nitrogen, Carbon isotopes (e.g., C12, C13, C14) Hydrogen, Oxygen, Vacancies, and the like) on the absorption of EM radiation, at given ambient temperature and / or stress conditions. System 100 may subsequently use calibration table 320T to omit this effect from subsequent, EM absorption measurements in real-time, thereby accurately determining the value of one or more lattice data elements 300L.

[0119] As shown in Fig. 4, evaluation module 300 may include a spectrum analysis module 330. Spectrum analysis module 330 may perform spectral analysis of the absorption data element 310AB, in order to obtain lattice data element 300L.

[0120] For example, spectrum analysis module 330 may apply (e.g., pointwise-subtract) table 320T on absorption data element 310AB to obtain a calibrated absorption spectrum data element 33OSP. Calibrated absorption spectrum data element 33OSP may represent an absorption spectrum of the specific at least one diamond 120, that is devoid of the effect of diamond- specific structural variations. According to some embodiments, calibrated absorption spectrum data element 33OSP may represent a plurality of spectra, each pertaining to specific environmental conditions such as stress and / or temperature in which device 10 resides.

[0121] In that respect, calibrated absorption spectrum data element 33OSP may include similar information to an ODMR spectrum, such as exemplified and explained herein (e.g., in relation to Fig. 2). However, as may be appreciated by a person skilled in the art, device 10 may provide calibrated absorption spectrum data element 33OSP in real-time, using a single measurement of EM energy absorption, whereas currently available ODMR systems would require a multitude fluorescence readings, each corresponding to a respective EM frequency.

[0122] Additionally, or alternatively, spectrum analysis module 330 may include, or may be associated with one or more modules (e.g., 340, 350, 360, 370, 380). As explained herein,each of modules 340, 350, 360, 370, 380 may be adapted to analyze calibrated absorption spectrum data element 33OSP, to obtain lattice data elements 300L representing respective, unique data types.

[0123] According to some embodiments, device 10 may further include a light source, such as a laser emitter. Light source 200 may be adapted to emit light 200L, e.g., as one or more laser pulses, or as constant wave (CW) laser emission. The frequency of light 200L may be appropriately selected to excite the point defects 120PD into fluorescence of photons. For example, when using NV centers as point defects 120PD, a 532 nm (green) laser beam may be selected for excitation, as known in the art.

[0124] As explained herein (e.g., in relation to Fig. 1), illumination of point defects 120PD may not only excite the point defects 120PD (e.g., NV centers) to an excited energy state, but also preferentially transfer electrons from the ms=±l spin- states of the excited state to a metastable state, from which they decay preferentially to the ms = 0 spin-state of the ground state.

[0125] In other words, the at least one controller 2 of Fig. 3 may control light source 200 to emit light 200L, thereby initializing the energy state of point defects 120PD in the diamond lattice 120 to the ms = 0 spin- state of the ground state.

[0126] During an initial calibration stage, controller 2 may control light source 200 to initialize the energy state of point defects 120PD, to obtain an initial difference signal 430D. This initial difference signal 430D may characterize impairments of a specific diamond, when point defects are at the initialized state. In other words, RF absorption of the diamond as represented by the initial difference signal 430D may indicate baseline-characteristics of that diamond at a given ambient surrounding of temperature, stress, magnetic field and electromagnetic radiation. Controller 2 may thus perform spectral analysis of the initial EM difference signal 430D, to generate calibration table 320T.

[0127] According to some embodiments, the at least one controller 2 may be configured (e.g., at a subsequent, operational stage) to compute the lattice data element 300L repeatedly, over a plurality of iterations. Each iteration may, for example, pertain to a different timestamps, e.g., to study temporal changes in properties of inherent to diamond lattice 120 and / or its surroundings.

[0128] In another example, each iteration may pertain to a different point defect 120PD location: e.g., a different diamond, a different point defect 120PD or cluster of point defects 120PD within the same diamond, etc.

[0129] In another example, each iteration may pertain to a differently applied environmental parameter, such as a different EM frequency bands, a different applied magnetic field, a different applied stress or temperature, and the like. Any combination of the above examples is also possible.

[0130] In each iteration, controller 2 may control light source 200 to emit light 200L, thereby initializing point defects’ 120PD energy states at the ground state prior to each measurement. Controller 2 may then control transmitter 110TX, to transmit EM signal 110RF through the at least one diamond 120.

[0131] As elaborated herein, controller 2 may subsequently obtain a reading 130RF of the received EM signal from at least one receiver 130RX. Based on reading 130RF, controller 2 may calculate absorption data element 310AB and / or spectrum data element 33OSP, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond 120. Controller 2 may then analyze the absorption data element 310AB and / or spectrum data element 33OSP, to compute the lattice data element 300L pertaining to that measurement iteration.

[0132] Reference is also made to Fig. 6, which is a schematic diagram, depicting another example of sensor 100 (as in Fig. 4), that may be included in system 10, or device 10 (as in Fig. 4), for sensing a physical condition in a crystal lattice, according to some embodiments of the invention.

[0133] The example depicted in Fig. 6, emphasizes usage of sensor 100 in the capacity of sensing, or calculating a quantum state value 340QS (e.g., a spin-state) of at least one point-defect 120PD. It may be appreciated by a person skilled in the art that calculation of a quantum state value may enable a variety of applications: For example, as depicted in Fig. 6, point-defect 120PD may be used to implement a qubit, e.g., for use in a quantum computer, where spin- states ms = +1, -1 of point-defect 120PD may represent positive and negative qubit-data values. In this context, the terms “qubit” and point-defect 120PD may be used interchangeably to indicate a receptacle of a quantum-data bit.

[0134] As shown in the example of Fig. 6, each qubit may be implemented as a single point-defect 120PD in a dedicated diamond 120. In such implementations, each qubit maybe associated with a respective, dedicated emission element (e.g., transmission antenna) 115AN, reception element (e.g., reception antenna) 135AN, and light source 200.

[0135] Additionally, or alternatively, two or more qubits may be implemented as two or more respective point-defects 120PD in a single diamond 120. In such implementations, a single emission element 115 AN and a single light source 200 may be allocated to that diamond, and the two or more qubits may share the emission element 115AN and light source 200. Other such combinations may also be possible.

[0136] According to some embodiments, the at least one controller 2 may control the at least one transmitter 110TX to transmit an EM signal 110RF at a predetermined microwave frequency via the emission element 115AN. As known in the art, such transmission may affect the spin-quantum state of at least one point defect 120PD, thereby writing qubit-data into at least one respective qubit.

[0137] Additionally, or alternatively, sensor 100 may include a magnetic field inductor 140. Magnetic field inductor 140 may, for example, may be implemented as a permanent magnet, or an electromagnetic coil. Magnetic field inductor 140 may be associated with, or juxtaposed to one or more point defects 120PD, to induce a magnetic field at a location of the one or more point defects. As exemplified in Fig. 1 , under the effect of the magnetic field induced by magnetic field inductor 140, the spin-states ms= 0, -1, 1 of point defects 120PD may split due to the Zeeman effect. Controller 2 may therefore determine the microwave frequency based on intensity of the induced magnetic field.

[0138] Pertaining to the example of Fig. 1, controller 2 may control electromagnet 140 to induce a magnetic field 140B so as to split the energy levels of ms=+l and -1 around 2.87 GHz, e.g., such that ms=-l will correspond to EM radiation 110RF of 2.88 GHz, and ms=+l will correspond to EM radiation 110RF of 2.86 GHz. In order to write, or store qubit-data into the qubit (into point defect 120PD), controller 2 may then control transmitter 110TX to transmit an EM signal 110RF at a predetermined microwave frequency (e.g., 2.86, 2.87 or 2.88 GHz) according to the intended qubit-data (e.g., I+1>, superposition or l-l>, respectively).

[0139] As known in the art, In order to read a spin state of an NV center, currently available ODMR system sweep through RF frequencies in a multitude of iterations. In each such iteration, a laser source is used to excite the NV centers (e.g., state 3E of Fig. 1), andthe subsequent, RF-frequency-specific fluorescence is measured to determine the NV center’s spin- state.

[0140] In contrast, and as explained herein, sensor 100 may read the qubit-data stored in one or more qubits, (respectively represented by one or more point defects 120PD), using a single measurement, and based on the EM absorption spectrum 33OSP rather than on individual fluorescence values, allowing embodiments of the invention to use point defects 120PD in a variety of real-time applications.

[0141] As shown in Fig. 4, evaluation module 300 may include a Quantum State (QS) calculation module 340 (or QS module 340, for short). QS module 340 may be adapted to receive calibrated absorption spectrum data element 33OSP, and calculate lattice data element 300L (e.g., spin quantum state value 340QS) based on data element 33OSP.

[0142] Pertaining to the above example, where quantum state value 340QS may represent a spin quantum state (e.g., ms=0, -1 or 1) of one or more point defects 120PD (e.g., corresponding to a value of one or more respective qubits): In this example, calibrated absorption spectrum data element 33OSP may include a dip or peak in a frequency that corresponds to the spin qubit state (e.g., one of 2.88 and 2.86 GHz). QS module 340 may detect this dip or peak, thereby identifying quantum state value 340QS (e.g., spin-state n+1) in the lattice at least one diamond 120. QS module 340 may thus produce lattice data element 300L as a representation, or a reading of qubit-data, as manifested by the spin-quantum state of the one or more qubits 120PD.

[0143] Reference is now made to Fig. 7A, which is a schematic diagram, depicting an isometric view of components of an array 100AR of sensors 100, such as sensor 100 of Fig. 4. The array 100AR of sensors 100 may be included in a system 10, or device 10 (e.g., the same as in Fig. 4) for sensing a physical condition in a crystal lattice, or a plurality of crystal lattices, according to some embodiments of the invention. Reference is also made to Figs. 7B and 7C, which are schematic diagrams, depicting components of array 100AR of Fig. 7A, according to some embodiments of the invention.

[0144] According to some embodiments, controller 2 may control the components of each of sensors 100 individually, or as a group, to generate calibrated absorption spectrum data element 33OSP for one or more (e.g., each) sensor 100. System 10 may include one or more evaluation modules 300, adapted to calculate lattice data elements 300E pertaining to one or more (e.g., each) sensor 100 of array 100AR. For example, the one or more QScalculation modules 340 of the one or more evaluation modules 300 may instantaneously write, and / or read qubit-data of one or more qubits (e.g., point defects 120PD) in one or more sensors 100 of array 100 AR.

[0145] As shown in Fig. 4, evaluation modules 300 may include a magnetic field calculation module 360. Module 360 may collaborate with quantum state calculation module 340 to calculate at least one of an amplitude of a magnetic field at the one or more point defects 120PD, and a polarization of a magnetic field at the one or more point defects 120PD:

[0146] As explained herein, an induced magnetic field will affect the splitting of spinenergy levels (ms = 0, ±1) in ground state 3A2. Therefore, dips or peaks of calibrated absorption spectrum data element 33OSP, which correspond to those spin-energy levels would be shifted from their baseline values (e.g., 2.86 GHz and 2.88 GHz in the above example). Magnetic field calculation module 360 may measure a shift EM RF frequency in the dips or peaks of data element 33OSP in relation to their baseline values. Module 360 may thereby generate a lattice data element 300L which indicates a momentary amplitude 360B of a magnetic field at the location of point defect 120PD. Additionally, of alternatively, lattice data element 300L may indicate a momentary polarization 360B of a magnetic field at the location of point defect 120PD.

[0147] Each sensor 100 of array 100AR may be used by controller 2 to indicate a momentary, real-time value of a property 360B (e.g., amplitude, polarization) of a magnetic field at the location of that sensor 100. Therefore, embodiments of the invention may be regarded as a “camera”, designed to generate an array data structure, or an “image” of a magnetic field at the location of array 100AR. In such embodiments, each sensor 100 or diamond 120 of array 100AR may serve as a pixel-sensor. Controller 2 may subsequently aggregate the lattice data 300L (e.g., magnetic property 360B) from the plurality of sensors 100 or diamonds as a two-dimensional (2D) array, to produce a magnetic “image” 360BI, depicting a momentary magnetic field or a magnetic “scene”.

[0148] Additionally, or alternatively, embodiments of the invention may implement a magnetic imaging apparatus that includes an array or plurality (denoted 10PL) of devices 10. Each instance (device 10) of the magnetic imaging apparatus 10P may correspond to a pixel in a magnetic “image”. Each instance (device 10) of the magnetic imaging apparatus 10P may be configured to produce a lattice data element 300L representing magnetic property 360B such as an amplitude or polarization of a magnetic field at its respective pointdefects 120PD. Imaging apparatus 10PL may thereby produce an image of amplitude and / or polarization of a magnetic field at the location of instances (devices) 10.

[0149] Additionally, or alternatively, embodiments of the invention may implement a new type of magnetic “radar”. As shown in Fig. 4, device 10 (or imaging apparatus 10PL) may include an RF radiation emitter module 500. RF emitter 500 may be adapted to transmit RF radiation 510RF of a predetermined frequency, according to a specific application.

[0150] Device 10 (or the magnetic imaging apparatus) may then use the array 100AR of sensors 100 (or plurality 10PL of devices 10) to receive reflection of the emitted RF radiation 510RF from surrounding objects, to produce an image 360BI of a magnetic component of the reflected RF radiation.

[0151] It may be appreciated that intelligent selection of RF radiation 51 ORF frequency, in combination with the real-time property of spectral absorption analysis of evaluation module 300 may allow device 10 (or the magnetic imaging apparatus 10PL) to facilitate some unique imaging capabilities. For example, RF radiation 510RF may be determined or selected so as to penetrate specific objects or materials (e.g., walls), allowing embodiments of the invention to “see” through these objects and materials (e.g., “see” through walls).

[0152] Additionally, or alternatively, lattice data 300L may represent a physical condition such as a stress of the at least one diamond’s lattice at the one or more point defects 120PD, and / or a temperature at the one or more point defects 120PD:

[0153] As known in the art, an ODMR spectrum may be affected by lattice stress and / or temperature. As shown in the example of Fig. 1, a temperature at a location of an NV center may be calculated based on the ODMR spectrum, given a predetermined level of stress and ambient magnetic field. In a similar manner, a lattice stress at a location of an NV center may be calculated based on the ODMR spectrum, given a predetermined temperature and ambient magnetic field.

[0154] As shown in Fig. 4, evaluation modules 300 may include a temperature calculation module 350. As explained herein, given a base-level of ambient magnetic field amplitude and / or lattice stress, dips or peaks in values of calibrated absorption spectrum data element 33OSP (representing quantum states 340QS of point defects 120PD) may be shifted due to temperature at the one or more point defects 120PD. Module 350 may therefore collaborate with quantum state calculation module 340 to calculate this shift, therebyproducing a lattice data element 300L that represents temperature 350T at the one or more point defects 120PD.

[0155] Additionally, or alternatively, evaluation modules 300 may include a stress calculation module 370. As explained herein, given a base-level of ambient magnetic field amplitude and / or temperature, dips or peaks in values of calibrated absorption spectrum data element 33OSP (representing quantum states 340QS of point defects 120PD) may be shifted due to stress at the one or more point defects 120PD. Module 350 may therefore collaborate with quantum state calculation module 340 to calculate this shift, thereby producing a lattice data element 300L that represents lattice stress 370S at the one or more point defects 120PD.

[0156] Reference is now made to Fig. 8 is a flow diagram, depicting a method of sensing a physical condition in a crystal lattice, according to some embodiments of the invention.

[0157] As shown in step S1005, embodiments of the invention may include obtaining at least one diamond (e.g., diamond 120 of Figs. 4, 5 and / or 7C) having a lattice that may include one or more point defects (e.g., point defects 120PD of Fig. 4).

[0158] As shown in step S1010, embodiments of the invention may include controlling, by at least one processor or controller (e.g., controller of Fig. 3) a light source (e.g., light source 200 of Fig. 4) to emit a pulse of light (e.g., 200L of Fig. 4) at an appropriate frequency to excite the point defects 120PD into fluorescence of photons, thereby initializing the point defects’ 120PD energy state at a ground state (e.g., msO of 3A2 in Fig. 1).

[0159] As shown in step S1015, the at least one controller 2 may control a transmitter (e.g., 100TX of Fig. 4) to transmit an EM signal at a predefined band of micro wave frequency via an emission element (e.g., transmission antenna 115AN of Fig. 4) through the at least one diamond 120.

[0160] As shown in step S 1020, embodiments of the invention may include receiving the EM signal from the at least one diamond 120, by at least one receiver (e.g., 130RX of Fig. 4), via at least one respective reception element (e.g., receiver antenna 135AN of Fig. 4).

[0161] As shown in steps S1025 and S1030, the at least one controller 2 may obtain a reading (e.g., 130RF of Fig. 4) of the received EM signal from the at least one receiver 130RX. Based on reading 130RF, the at least one controller 2 may calculate an absorption data element 310AB and / or a spectrum data element 33OSP. As elaborated herein (e.g., in relation to Fig. 4), absorption data element 310AB and / or a spectrum data element 33OSPmay represent absorption of the transmitted EM signal 110RF at the predetermined frequency band in the at least one diamond 120.

[0162] As shown in step S1035, controller 2 may subsequently analyze the absorption data element 310AB and / or a spectrum data element 33OSP to compute a lattice data element 300L. As elaborated herein (e.g., in relation to Fig. 4), lattice data element 300E may represent an inherent, or induced physical condition of the one or more point defects in the diamond.

[0163] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Furthermore, all formulas described herein are intended as examples only and other or different formulas may be used. Additionally, some of the described method embodiments or elements thereof may occur or be performed at the same point in time.

[0164] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0165] Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.

Claims

CLAIMS1. A device for sensing a physical condition in a lattice, the device comprising: at least one diamond, having a lattice comprising one or more point defects; at least one transmitter, adapted to transmit an electromagnetic (EM) signal at a predefined band of microwave frequency, via a respective emission element, through the at least one diamond; at least one receiver, adapted to receive the EM signal from the at least one diamond, via a respective reception element; and at least one controller, associated with said receiver, and configured to compute a lattice data element, representing a physical condition of the one or more point defects in the at least one diamond, based on the received EM signal.

2. The device of claim 1, wherein at least one diamond comprises a single point defect, and wherein the lattice data element represents a physical condition of the single point defect.

3. The device according to any one of claims 1-2, wherein at least one diamond comprises an assembly of single point defects, located at a minimal predetermined distance from one another, and wherein the lattice data element represents a physical condition of each of the single point defects.

4. The device according to any one of claims 1-3, wherein the physical condition is a quantum state of the one or more point defects in the lattice of the at least one diamond.

5. The device according to any one of claims 1-4, wherein the one or more point defects respectively represent one or more quantum bits (qubits), and wherein the physical condition of the one or more point defects is a spin-quantum state corresponding to a value of the respective one or more qubits, and wherein the lattice data element represents a reading of qubit-data, as manifested by the spin-quantum state of the one or more qubits.

6. The device of claim 5 wherein the at least one controller is further configured to control the at least one transmitter, so as to transmit an EM signal at a predetermined microwave frequency via the emission element, to affect the spin-quantum state of at least one point defect, thereby writing qubit-data into at least one respective qubit.

7. The device of claim 6 wherein one or more point defects are associated with one or more respective magnetic field inductors or magnets, configured to induce a magnetic field at a location of the one or more point defects, and wherein the controller is further configured to determine the microwave frequency based on intensity of the induced magnetic field.

8. The device according to any one of claims 1-7, wherein the physical condition is selected from an amplitude of a magnetic field at the one or more point defects, and a polarization of a magnetic field at the one or more point defects.

9. The device according to any one of claims 1-8, wherein the physical condition is further selected from a stress of the at least one diamond’s lattice at the one or more point defects, and temperature at the one or more point defects.

10. The device according to any one of claims 1-9, wherein the point defects are selected from a list consisting of: Nitrogen- Vacancy (NV) centers, Silicon- Vacancy (SV) centers, Germanium- Vacancy (GeV) centers, Led-Vacancy (PbV) centers, and Tin-Vacancy (SnV) centers.

11. The device according to any one of claims 1-10, wherein the at least one controller is configured to compute the lattice data element by: obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal in the at least one diamond; and performing spectral analysis of the absorption data element, to compute the lattice data element.

12. The device according to any one of claims 1-11, further comprising a light source, adapted to emit light at an appropriate frequency to excite the point defects into fluorescence of photons, thereby initializing their energy state at a ground state.

13. The device of claim 12, wherein the at least one controller is configured to compute the lattice data element repeatedly, over a plurality of iterations, wherein each iteration comprises the steps of: controlling the light source to initialize the point defects’ energy states at the ground state; controlling the transmitter, to transmit the EM signal through the at least one diamond; obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond; and analyzing the absorption data element, to compute the lattice data element.

14. The device according to any one of claims 1-13, wherein the absorption data element comprises a point-wise difference between a spectral distribution of the transmitted EM signal and a spectral distribution of the received EM signal.

15. The device according to any one of claims 1-14, further comprising a calibration module, and wherein the controller is further configured to: utilize the calibration module to generate a calibration table, representing a spectrum of absorption of EM frequencies, by the specific at least one diamond; and compute the lattice data element further based on the calibration table, to compensate for irregularities in the specific, at least one diamond.

16. The device of claim 15, wherein the calibration module comprises: an EM power splitter, configured to split the transmitted EM signal to a measurement path, that traverses the at least one diamond, and a reference path; a phase shifter, located in the reference path, and configured to produce a delayed version of the transmitted EM signal; anda mixer module, adapted to generate an EM difference signal, representing a difference between (i) the delayed version of the transmitted EM signal and (ii) the received EM signal at the reception element.

17. The device of claim 16, wherein the controller is further configured to control the phase shifter based on the EM difference signal, so as to compensate for at least one of (a) difference in EM propagation between the reference path and measurement path, and (b) phase inconsistencies in the transmitted EM signal.

18. The device according to any one of claims 16-17, wherein the at least one controller is configured to perform spectral analysis of the EM difference signal, and generate the calibration table based on that spectral analysis.

19. A magnetic imaging apparatus comprising an array of instances of the device according to any one of claims 1-18, wherein each instance corresponds to an image pixel, and wherein each instance is configured to produce a lattice data element representing an amplitude or polarization of a magnetic field at its point defects, thereby producing an image of amplitude or polarization of a magnetic field.

20. The magnetic imaging apparatus of claim 19 further comprising an RF emitter, configured to emit RF radiation, and wherein the array of instances is configured to receive reflection of the emitted RF radiation from surrounding objects, to produce an image of a magnetic component of the reflected RF radiation.

21. The device according to any one of claims 1-20, wherein the at least one emission element is a transmission antenna, and the at least one reception element is a receiver antenna, and wherein at least one of the receiver antenna and transmitter antenna is embedded within the diamond.

22. A method of sensing a physical condition in a lattice, the method comprising: obtaining at least one diamond having a lattice comprising one or more point defects;controlling, by at least one controller, a light source to emit a pulse of light at an appropriate frequency to excite the point defects into fluorescence of photons, thereby initializing their energy state at a ground state; transmitting an EM signal at a predefined band of microwave frequency through the at least one diamond; receiving the EM signal from the at least one diamond by at least one receiver; obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating, by the at least one controller, an absorption data element, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond; and analyzing, by the at least one controller, the absorption data element, to compute a lattice data element representing a physical condition of the one or more point defects in the diamond.

23. The method of claim 22, wherein at least one diamond comprises a single point defect, and wherein the lattice data element represents a physical condition of the single point defect.

24. The method according to any one of claims 22-23, wherein at least one diamond comprises an assembly of single point defects, located at a minimal predetermined distance from one another, and wherein the lattice data element represents a physical condition of each of the single point defects.

25. The method according to any one of claims 22-24, wherein the physical condition is a quantum state of the one or more point defects in the lattice of the at least one diamond.

26. The method according to any one of claims 22-25, wherein the one or more point defects respectively represent one or more quantum bits (qubits), and wherein the physical condition of the one or more point defects is a spin-quantum state corresponding to a value of the respective one or more qubits, and wherein the lattice data element represents a reading of qubit-data, as manifested by the spin-quantum state of the one or more qubits.

27. The method of claim 26 wherein the at least one controller is further configured to control the at least one transmitter, so as to transmit an EM signal at a predetermined microwave frequency via the emission element, to affect the spin-quantum state of at least one point defect, thereby writing qubit-data into at least one respective qubit.

28. The method of claim 27, further comprising: obtaining one or more magnetic field inductors or magnets, associated with one or more respective point defects, wherein said magnetic field inductors or magnets, configured to induce a magnetic field at a location of the one or more point defects; and determining the microwave frequency by the at least one controller, based on intensity of the induced magnetic field.

29. The device according to any one of claims 22-28, wherein the physical condition is selected from an amplitude of a magnetic field at the one or more point defects, and a polarization of a magnetic field at the one or more point defects.

30. The method according to any one of claims 22-29, wherein the physical condition is further selected from a stress of the at least one diamond’s lattice at the one or more point defects, and temperature at the one or more point defects.

31. The method according to any one of claims 22-30, wherein the point defects are selected from a list consisting of: Nitrogen- Vacancy (NV) centers, Silicon- Vacancy (SV) centers, Germanium- Vacancy (GeV) centers, Led-Vacancy (PbV) centers, and Tin-Vacancy (SnV) centers.

32. The method according to any one of claims 22-31 , further comprising: obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal in the at least one diamond, by the at least one controller; and performing spectral analysis of the absorption data element by the at least one controller, to compute the lattice data element.

33. The method according to any one of claims 22-32, wherein the at least one controller is configured to compute the lattice data element repeatedly, over a plurality of iterations, wherein each iteration comprises the steps of: controlling the light source to initialize the point defects’ energy states at the ground state; controlling the transmitter, to transmit the EM signal through the at least one diamond; obtaining a reading of the received EM signal from the at least one receiver; based on said reading, calculating an absorption data element, representing absorption of the transmitted EM signal, at the predetermined frequency band in the at least one diamond; and analyzing the absorption data element, to compute the lattice data element.

34. The method according to any one of claims 22-33, wherein the absorption data element comprises a point- wise difference between a spectral distribution of the transmitted EM signal and a spectral distribution of the received EM signal.

35. The method according to any one of claims 22-34, further comprising: obtaining a calibration module; and controlling the calibration module by the at least one controller, to generate a calibration table, wherein said calibration table represents a spectrum of absorption of EM frequencies, by the specific at least one diamond; and computing the lattice data element by the at least one controller, further based on the calibration table, to compensate for irregularities in the specific, at least one diamond.

36. The method of claim 35, wherein obtaining the calibration module comprises: obtaining an EM power splitter, configured to split the transmitted EM signal to a measurement path, that traverses the at least one diamond, and a reference path; obtaining a phase shifter, located in the reference path, and configured to produce a delayed version of the transmitted EM signal; and employing a mixer module to generate an EM difference signal, wherein the EM difference signal represents a difference between (i) the delayed version of the transmitted EM signal and (ii) the received EM signal at the reception element.

37. The method of claim 36 further comprising controlling the phase shifter by the at least one controller, based on the EM difference signal, so as to compensate for at least one of (a) difference in EM propagation between the reference path and measurement path, and (b) phase inconsistencies in the transmitted EM signal.

38. The method according to any one of claims 36-37 further comprising: performing spectral analysis of the EM difference signal by the at least one controller; and generating the calibration table by the at least one controller, based on that spectral analysis.

39. The method according to any one of claims 22-38 further comprising: obtaining an array of instances of the at least one diamond of claim 22, wherein each instance corresponds to an image pixel; and producing, for each instance, a lattice data element representing an amplitude or polarization of a magnetic field at its point defects, thereby producing an image of amplitude or polarization of a magnetic field.

40. The method of claim 39 further comprising: obtaining an RF emitter, configured to emit RF radiation; configuring the array of instances is configured to receive reflection of the emitted RF radiation from surrounding objects; and producing, by the at least one controller, an image of a magnetic component of the reflected RF radiation.

41. The method according to any one of claims 22-40, wherein the at least one emission element is a transmission antenna, and the at least one reception element is a receiver antenna, and wherein at least one of the receiver antenna and transmitter antenna is embedded within the diamond.

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